CommercialToolry

Understanding Pro Carbon Ping Pong Paddle: Standards, Properties, and Applications

Types of Professional Carbon Ping Pong Paddles

A professional carbon ping pong paddle is engineered for elite players who demand maximum speed, control, and spin response. These paddles incorporate carbon fiber layers bonded with wood plies to enhance rigidity and energy transfer, allowing for explosive ball speed with minimal effort. This makes them ideal for aggressive, fast-paced playing styles and advanced techniques used in competitive table tennis.

Understanding the different types of carbon paddles—based on construction, grip, spin capabilities, and rubber composition—can help players choose the right equipment to match their skill level and playing strategy.

By Ply Construction

Carbon paddles are classified by the number of layers (plies), combining wood and carbon fiber to balance speed, control, and feel.

  • 2-Ply: Features two carbon layers over a dual wood core. Offers exceptional speed and stiffness, ideal for offensive players who rely on quick attacks.
  • 3-Ply: Includes three carbon layers laminated between wood plies. Provides enhanced rigidity and faster rebound, suitable for aggressive loop drives and smashes.
  • 5-Ply: Typically consists of five wood layers with carbon fibers integrated into alternating plies (e.g., wood-carbon-wood-carbon-wood). Delivers a balanced blend of control and speed, perfect for all-around players.
  • 7-Ply: Primarily carbon-dominant with a 5-ply wood structure reinforced by carbon. Maximizes stiffness and ball velocity, favored by professional attackers and power players.

Best for: Advanced players seeking precision, speed, and dynamic response based on playing style

By Grip Type

The grip determines comfort, control, and maneuverability. Choosing the right grip enhances stroke consistency and reduces hand fatigue.

  • Straight Grip: Uniform width from top to bottom. Offers symmetrical balance and is ideal for shakehand players who prefer neutral hand positioning and all-around play.
  • Flared Grip: Widens at the base for a secure fit in the palm. Provides excellent control and stability, especially during powerful forehand strokes and extended rallies.
  • Anatomical (Ergonomic) Grip: Contoured to match the natural shape of the hand. Enhances comfort and reduces slippage, making it ideal for players with larger hands or those who play long matches.

Best for: Players prioritizing comfort, control, and reduced hand strain during intense gameplay

By Spin Performance

Different paddles are optimized for generating specific types of spin, crucial for outmaneuvering opponents.

  • Topspin Paddles: Feature high-tension rubber with a thick sponge layer that grips the ball and facilitates upward brushing motion. Enables deep, aggressive loops with heavy forward rotation.
  • Sidespin Paddles: Use specially textured rubber and variable hardness to create lateral spin. Causes the ball to curve sideways after bouncing, disrupting timing and positioning.
  • All-Round Spin Paddles: Designed with balanced rubber and moderate sponge to support both topspin and backspin techniques, ideal for versatile players.

Best for: Offensive players focusing on spin variation and tactical ball placement

By Rubber Composition

The rubber surface significantly affects spin, speed, and control. Professional paddles use advanced rubber technologies tailored to specific play styles.

  • Sticky Rubber: High-friction surface that "grips" the ball on contact. Ideal for offensive players who generate heavy spin and quick attacks close to the table.
  • Hybrid Rubber: Combines smooth and pimpled textures on a single side or uses dual-density sponge. Offers versatility for both aggressive loops and defensive chops.
  • Pips-Out Rubber: Features outward-facing pimples that reduce spin interaction. Allows for fast, low-spin returns and is excellent for counter-hitting and disrupting rhythm.

Best for: Players customizing their game with specialized spin and speed profiles

Feature Type Speed Control Ideal For
Construction 2-Ply / 3-Ply High Medium Offensive, fast attackers
Construction 5-Ply Medium-High High All-around players
Construction 7-Ply Very High Medium Power hitters, pros
Grip Straight Medium High Shakehand, balanced play
Grip Flared / Anatomical Medium Very High Control-focused, comfort
Spin Topspin High Medium Loopers, aggressive play
Rubber Sticky High Medium Spin-heavy offense
Rubber Pips-Out High Low-Medium Counter-drives, anti-spin

Expert Tip: When selecting a carbon paddle, consider your playing style first. Offensive players should prioritize 5- or 7-ply paddles with sticky rubber and flared grips, while all-around players benefit from 5-ply constructions with hybrid rubber and straight grips for versatility.

Design of Pro Carbon Ping Pong Paddle

The design of a professional-grade carbon fiber ping pong paddle is a sophisticated balance of materials, geometry, and ergonomics, engineered to enhance performance, control, and responsiveness. Modern pro paddles incorporate advanced composite technologies to optimize speed, spin, and feel. Below is a detailed breakdown of the key design elements that define high-performance carbon paddles.

Sponge Thickness: Power, Spin, and Control

The sponge layer beneath the rubber surface plays a pivotal role in determining shot dynamics. Its thickness directly affects ball dwell time, rebound speed, and spin generation.

1.0 cm Sponge

Offers maximum dwell time and excellent energy return, ideal for aggressive topspin players. Provides deep ball trajectory and enhanced spin potential, making it suitable for offensive looping styles.

1.5 cm Sponge

Delivers a balanced mix of spin and control. Slightly reduced depth compared to 1.0 cm, but offers improved consistency for mid-distance rallies and controlled attacks.

2.0 cm Sponge

Despite being labeled "thin" in some contexts, this likely refers to a misstatement—standard sponge thicknesses range from 1.0–2.5 mm, not cm. Assuming correction: a 2.0 mm sponge is medium-thick, favoring flat drives and fast placement with moderate spin. Ideal for close-to-table attackers.

2.5 mm Sponge (Maximum Thickness)

The thickest standard sponge, offering superior catapult effect and deep, spin-heavy shots. Best suited for players who rely on heavy topspin loops and all-around offensive play. Requires precise timing and technique.

Note: Sponge thickness in table tennis is typically measured in millimeters (mm), not centimeters (cm). The original text appears to contain a unit error. Standard ranges are 1.0–2.5 mm. This guide assumes corrected values for accuracy.

Paddle Shape: Surface Area and Play Style

The blade shape influences the sweet spot size, maneuverability, and swing efficiency.

Elongated Shape

Features an extended blade length for increased reach and a higher sweet spot. Enhances inverted strokes and looping from a distance. Preferred by players with aggressive backhand flicks and deep topspin rallies.

Standard Shape

Offers a balanced blend of control, power, and agility. Suitable for all-round players who switch between offense and defense. Provides consistent performance across various stroke types.

Wide-Body Shape

Expands the hitting surface laterally, increasing the margin for error on off-center hits. Ideal for beginners, defensive players, or those prioritizing stability over extreme speed. May slightly reduce wrist maneuverability.

Paddle Weight: Balance Between Speed and Control

Weight distribution and total mass affect swing speed, power transfer, and fatigue resistance.

Lightweight (75–80g)

Made with carbon-soaked layers for reduced mass. Enables rapid wrist action, quick transitions, and enhanced control. Favored by close-to-table attackers and players with fast reaction styles.

Midweight (81–85g)

Strikes an optimal balance between power and precision. Offers sufficient heft for strong counter-drives while maintaining agility. Recommended for intermediate to advanced all-round players.

Heavyweight (86g+)

Constructed with dense carbon composites for maximum power and stability. Excels in generating forceful topspins and blocking heavy attacks. May increase strain on the wrist during prolonged use.

Handle Design: Grip and Maneuverability

The handle length and shape influence grip comfort, rotational control, and stroke execution.

Short Handle

Provides quicker response and enhanced nimbleness. Ideal for penhold or shakehand grips requiring rapid directional changes. Offers less leverage for heavy loops but improves close-range control.

Long Handle

Enables greater torque and rotational power, beneficial for looping and powerful forehand strokes. Offers improved wrist support and balance, though slightly reduces flick speed and compactness.

Edge Guard: Protection and Performance Trade-offs

Edge protection helps preserve the blade structure and sponge integrity during impacts.

Protective Strip (Rubber or Plastic)

Provides durable shielding against chipping and moisture. Adds minimal weight but may slightly dampen vibration feedback and reduce edge responsiveness.

Integrated Carbon Layer

Reinforces the blade perimeter using the same carbon composite as the core. Maintains lightweight performance while enhancing structural rigidity and edge durability—ideal for competitive play.

No Edge Guard

Maximizes the usable surface area and ensures direct ball contact with the rubber edge. Favored by players seeking pure feel and maximum spin efficiency, though more vulnerable to damage from collisions or drops.

Design Feature Impact on Performance Best For
Sponge Thickness (2.5mm) High spin, deep trajectory, strong catapult Offensive loopers, all-round attackers
Elongated Blade Shape Extended reach, higher sweet spot Backhand flick specialists, distance players
Midweight Paddle (81–85g) Balanced power and control All-round players, transition game
Long Handle Greater leverage and loop power Forehand-dominant players, spin generators
Integrated Carbon Edge Guard Durability without added weight Competitive players, frequent users

Important: When selecting a pro carbon paddle, consider your playing style, physical comfort, and long-term durability. Using incorrect specifications—such as overly thick sponges or excessively heavy blades—can lead to reduced control or repetitive strain injuries. Always test paddle characteristics in real-game scenarios before finalizing your choice.

Scenarios for Professional Carbon Ping Pong Paddles

Professional carbon ping pong paddles are engineered for advanced players seeking enhanced speed, control, and spin response. The integration of carbon fiber in the blade construction provides a stiffer, more responsive platform that amplifies power while maintaining precision. Below are key scenarios where carbon paddles excel, helping players maximize performance based on playing style, skill level, and competitive goals.

Fast Play Close to the Table

Carbon paddles are ideal for aggressive, close-to-the-table play due to their lightweight construction and rapid rebound characteristics. The stiffness of the carbon layer allows for quick wrist flicks and snap returns, enabling players to dominate fast-paced rallies with minimal follow-through.

  • Excellent for quick counter-drives and punch shots immediately after the serve or receive
  • Reduces dwell time on the ball, increasing shot speed and reducing opponent reaction time
  • Suitable for penhold and shakehand players who rely on reflexive blocking and rapid transitions

Best for: Offensive players using a short backswing and fast hand speed

Powerful Looping from Mid-Range

When executing loop drives from a slightly farther distance, carbon blades offer superior energy transfer, especially when paired with high-tension or tensor rubbers. The rigidity of the blade complements thick sponge layers, allowing players to generate heavy topspin with controlled aggression.

  • Enhances arc and spin on loop shots, making the ball dip sharply over the net
  • Ideal for players using inverted rubber on both sides for maximum spin generation
  • Supports consistent topspin rallies against backspin serves and pushes

Pro insight: Combine with soft to medium-hard rubber for optimal spin-to-speed ratio

Defensive Blocks and Returns

Despite their offensive reputation, carbon paddles can be highly effective in defensive scenarios. The stable blade structure absorbs impact from powerful smashes and spin-heavy loops, allowing for precise, controlled blocks with minimal vibration.

  • Stiff blade resists deformation under high-speed shots, improving shot consistency
  • Enables short, sharp blocks that return spin effectively without excessive rebound
  • Particularly useful in counter-looping situations where timing and placement matter more than raw power

Key benefit: Maintains control under pressure, even during intense spin battles

Competing in Tournaments

In high-stakes environments, professional players choose carbon paddles for their predictable response, enhanced sensitivity, and superior feedback. These paddles offer a refined balance of speed, control, and spin—critical for adapting to different opponents and match conditions.

  • Consistent performance across varied rubber combinations and playing styles
  • Responsive feel allows elite players to execute delicate touch shots (drops, flips) and explosive kills
  • Trusted by top-ranked players in ITTF-sanctioned events for reliability and precision

Tournament tip: Pre-match testing with your carbon blade ensures optimal rubber tension and blade responsiveness

Training Spin and Control

Carbon paddles are excellent training tools for mastering spin dynamics. Their responsive nature makes subtle differences in racket angle and stroke technique immediately apparent, helping players refine their touch and consistency.

  • Amplifies feedback on topspin, backspin, and sidespin execution for faster skill development
  • Works well with training rubbers (e.g., long pips, anti-spin) to simulate diverse opponent styles
  • Helps intermediate to advanced players transition from recreational to competitive play

Training advantage: Develop muscle memory faster due to immediate tactile response

Customization & Player Adaptability

Carbon paddles are often designed with modularity in mind, allowing players to tailor rubber combinations to their evolving style. Whether switching from offensive to all-round play, the carbon base remains versatile.

  • Compatible with a wide range of rubber types: tensor, high-tack, short pips, etc.
  • Enables fine-tuning of speed, spin, and weight distribution for personalized feel
  • Popular among players who frequently adjust equipment to counter specific opponents

Expert note: Regular maintenance (cleaning rubbers, checking blade integrity) extends paddle life and performance

Professional Recommendation: While carbon paddles offer superior performance, they require precise technique. Beginners may find them less forgiving due to reduced dwell time and higher speed. Intermediate to advanced players benefit most—especially those focusing on spin variation, quick transitions, and tactical consistency. For optimal results, pair your carbon blade with high-quality rubbers and practice regularly to exploit its full potential.

Playing Style Recommended Carbon Paddle Feature Optimal Rubber Type Performance Benefit
Aggressive close-to-table Lightweight, thin carbon layer Tensor or high-speed inverted Fast reaction, sharp counter-attacks
Mid-distance looper Double carbon layer, medium thickness High-spin inverted with 2.1mm+ sponge Maximum topspin and drive depth
All-round control player Hybrid carbon-wood core Balanced inverted rubber Stability with responsive touch
Defensive counter-player Stiff carbon frame with vibration damping Short pips or anti-spin Precise blocking and spin reversal

Additional Considerations

  • Durability: High-quality carbon blades resist warping and moisture damage, ensuring long-term reliability
  • Weight Distribution: Carbon layers can be placed differently (outer vs. inner) to adjust balance and swing weight
  • Regulation Compliance: ITTF-approved carbon paddles contain limited layers (usually 1–2) to maintain fair play standards
  • Grip Compatibility: Choose flared, anatomic, or straight handles based on hand size and playing style
  • Personalization: Many brands offer custom blade profiling and rubber pre-assembly for tournament players

Specification & Maintenance of Pro Carbon Ping Pong Paddle

High-performance carbon fiber ping pong paddles are precision-engineered tools designed for competitive play, combining lightweight strength with enhanced spin and control. To preserve their performance and extend their lifespan, proper care and regular maintenance are essential. This comprehensive guide outlines best practices for maintaining your pro carbon paddle, covering rubber care, storage, handle upkeep, blade inspection, and edge guard maintenance. Following these guidelines ensures consistent playability and protects your investment in top-tier equipment.

Important Notice: Even minor damage to the carbon layer or delamination between materials can significantly alter the paddle’s performance and may render it non-compliant in official tournaments. Always inspect your paddle before competition.

Rubber Care: Preserving Grip and Spin Performance

The rubber surface is the most critical component for generating spin and controlling ball trajectory. After every use, clean the rubber with a slightly damp cloth or a specialized table tennis rubber cleaner to remove dust, sweat, and oils that can degrade the tackiness over time. Avoid using alcohol-based cleaners or abrasive materials, as they can dry out or damage the rubber surface.

To maximize longevity, rotate the rubber by turning it inside out (if applicable) or using both sides evenly during practice. This prevents one side from wearing prematurely. Store the paddle in a protective cover away from direct sunlight and UV exposure, which can cause the rubber to harden, lose elasticity, and reduce spin potential. For long-term storage, consider applying a rubber protection sheet to shield the surface from oxidation.

Paddle Storage: Protecting Structural Integrity

Always store your paddle in a dedicated case or protective cover to prevent accidental impacts, pressure, or contact with sharp objects during transport. Exposure to extreme environmental conditions can compromise both the wood core and carbon composite layers. Avoid leaving the paddle in hot environments such as car trunks or near heating vents, as excessive heat can warp the blade or weaken the adhesive bonding the layers.

Likewise, extremely cold temperatures can make the rubber brittle and reduce the flexibility of the glue used in construction. High humidity or moisture can also affect the wood-to-carbon bond, potentially leading to delamination over time. Ideal storage conditions include a cool, dry place with stable temperature and low humidity (40–60% RH).

Handle Maintenance: Ensuring a Secure Grip

The handle should be wiped down after each use to remove sweat and oils that can degrade the grip material and lead to slippage during intense rallies. A clean, dry handle enhances control and reduces the risk of accidental drops. If the original grip becomes slippery or worn, consider replacing it with high-quality grip tape or an overgrip designed for table tennis paddles.

Overgrips are consumable items and should be replaced every few months depending on usage frequency. Signs of wear—such as cracking, fraying, or reduced tackiness—are indicators that replacement is needed. A compromised grip not only affects comfort but can also influence stroke consistency and overall paddle handling.

Blade Inspection: Maintaining Core Performance

Regularly inspect the blade for any signs of structural damage, including cracks, warping, or swelling, especially along the edges and around the handle joint. Pay close attention to the bond between the wooden plies and the carbon fiber layer. Any visible separation, bubbling, or peeling indicates delamination, which severely impacts the paddle’s stiffness, weight distribution, and responsiveness.

If you notice even a small gap or hear a hollow sound when gently tapping the blade, discontinue use and consider professional repair or replacement. A structurally compromised blade cannot deliver consistent performance and may fail during play.

Edge Guard Check: Shielding Against Impact Damage

The edge guard serves as a protective barrier for the vulnerable perimeter of the blade, where chipping or splintering is most likely to occur from accidental drops or collisions. Inspect the edge guard regularly for cracks, lifting, or missing sections. Damaged edge guards leave the internal layers exposed to moisture, dirt, and physical impact.

If damage is detected, replace the edge guard promptly using a compatible adhesive-backed replacement strip. Many manufacturers offer model-specific edge guards to ensure a precise fit. Properly maintained edge protection not only preserves aesthetics but also maintains the paddle’s balance and structural resilience.

Maintenance Area Recommended Frequency Key Tools/Supplies Performance Impact if Neglected
Rubber Surface After every use Damp cloth, rubber cleaner, protection sheet Reduced spin, loss of grip, uneven wear
Storage Conditions Ongoing Protective case, climate-controlled space Warping, delamination, rubber hardening
Handle & Grip After each session / every 1–3 months Clean cloth, replacement overgrip Slippage, poor control, inconsistent strokes
Blade Integrity Weekly or before tournaments Visual inspection, light tapping test Loss of power, unpredictable rebound, risk of breakage
Edge Guard Monthly or after impact Replacement edge tape, adhesive Increased vulnerability to chipping and moisture damage

Pro Tip: Create a maintenance log to track cleaning, grip changes, and inspections. Noting dates and observations helps identify wear patterns early and supports warranty claims if manufacturing defects arise.

Additional Recommendations for Longevity

  • Avoid placing heavy objects on top of your paddle in bags or drawers.
  • Never leave your paddle in a damp gym bag—allow it to air dry before storage.
  • Use separate compartments in your racket bag to prevent rubbing against other equipment.
  • Consider owning a backup paddle for training to reduce wear on your primary competition blade.
  • Follow manufacturer-specific care instructions, as advanced carbon composites may have unique requirements.

By adhering to these maintenance protocols, you ensure that your pro carbon ping pong paddle remains in peak condition, delivering reliable performance, optimal control, and extended durability. Remember: a well-maintained paddle is not only more effective but also more cost-efficient in the long run, reducing the need for frequent replacements.

Frequently Asked Questions About Table Tennis Paddles and Equipment

Q1: Do professional players use paddles with carbon technology?

Yes, many professional table tennis players choose paddles that incorporate carbon fiber technology due to the significant performance advantages it offers. Carbon layers are embedded within the blade to enhance rigidity and structural integrity, resulting in faster ball rebound, improved energy transfer, and greater control during high-speed rallies.

  • Enhanced Speed & Spin: The stiffness of carbon fibers allows for quicker snap-off on loops and drives, enabling players to generate more spin and pace without sacrificing accuracy.
  • Better Stability: Carbon-reinforced blades resist twisting on off-center hits, providing consistent feedback and improved shot placement—critical during aggressive play.
  • Controlled Power: While powerful, modern carbon blades are engineered to remain controllable, making them ideal for advanced techniques like counter-hitting, quick flicks, and deep topspin exchanges.
  • Popular Among Pros: Top players such as Ma Long, Fan Zhendong, and Timo Boll have used or endorsed carbon-layered blades, highlighting their effectiveness at elite levels.

However, carbon blades may not suit beginners, as they require precise technique to manage their responsiveness. For experienced players, though, the blend of speed, spin, and stability makes carbon technology a top choice in competitive play.

Q2: Which rubbers are suitable for different spin types?

The type of rubber on a paddle plays a crucial role in generating and handling spin. Different rubber surfaces cater to various playing styles and spin strategies. Here’s a breakdown of the most common types and their spin characteristics:

Rubber Type Best For Spin Characteristics Ideal Player Style
Tacky Rubber Topspin loops, aggressive forehand attacks High grip surface creates maximum topspin; excellent ball retention for heavy spin shots Offensive players who rely on spin-heavy loops and consistent rally control
Hybrid Rubber Balanced offense and defense, all-around play Moderate spin with enhanced speed; combines smooth topsheet with sponge elasticity for versatile spin options Intermediate to advanced players seeking adaptability in spin and pace
Pips-Out Rubber Blocking, chopping, and disrupting opponent's spin Produces less spin and reverses incoming spin; reduces predictability and counters aggressive topspin effectively Defensive or counter-driving players who prefer control over raw spin generation

Choosing the right rubber depends on your preferred spin strategy and overall playing style. Offensive players often favor tacky or hybrid rubbers for maximum spin potential, while defensive players may opt for pips-out to neutralize spin and create unpredictable returns.

Q3: What does a general maintenance routine look like for these paddles?

Proper maintenance is essential to preserve the performance, grip, and lifespan of your table tennis paddle, especially the sensitive rubber surface. A consistent care routine ensures optimal playability and prevents premature wear.

  • Clean After Every Use: Wipe the rubber surface with a dedicated rubber cleaner or a slightly damp microfiber cloth to remove dust, sweat, and dirt. Avoid water immersion or harsh chemicals that can degrade the sponge.
  • Dry Properly: Allow the paddle to air-dry completely before storing to prevent moisture buildup, which can cause bubbling or delamination.
  • Use a Protective Case: Store the paddle in a padded case away from direct sunlight, heat sources, and humidity to prevent rubber hardening and blade warping.
  • Check for Wear: Regularly inspect the rubber for cracks, peeling, or loss of tackiness. Replace worn rubbers promptly to maintain performance.
  • Rotate Replaceable Rubbers: If using removable rubbers, rotate them periodically to ensure even wear and extend their usable life.
  • Inspect Edge Guards: Make sure the edge tape or guard is intact to protect the blade from impacts and moisture ingress.

Following these steps can significantly extend the life of your paddle and keep it performing at its best, match after match.

Q4: What's the benefit of longer handle paddles?

Longer handle paddles—often referred to as "penhold" or "anatomic" handles—offer distinct advantages for players who rely on wrist flexibility, powerful loops, and dynamic stroke transitions.

  • Improved Wrist Mobility: The extended grip allows for greater wrist rotation, which enhances spin generation on looping shots and quick flicks.
  • Better Balance & Control: A longer handle shifts the balance point slightly toward the hand, improving maneuverability and reducing fatigue during extended rallies.
  • Secure Grip for Big Strokes: Players who stand farther from the table benefit from the extra leverage, enabling stronger backswing power and more controlled follow-through on aggressive drives.
  • Smooth Stroke Transitions: The design supports seamless switches between forehand and backhand, especially in penhold styles used by elite Asian players.
  • Reduced Mistakes on Complex Shots: Enhanced stability during large, sweeping motions helps minimize unforced errors in high-difficulty strokes.

While longer handles may take time to adjust to, they are particularly favored by offensive and spin-oriented players who value precision, power, and fluid technique over compact handling.

Q5: Is there a significant weight difference for heavyweight paddles?

Yes, heavyweight paddles typically weigh 2–4 ounces (approx. 170–190 grams) compared to lightweight models (150–165 grams), and this difference has a noticeable impact on gameplay.

  • Increased Shot Power: The added mass provides greater inertia, allowing players to drive through the ball with more force—ideal for powerful counter-hits, smashes, and deep topspin shots.
  • Enhanced Stability: Heavier paddles resist vibration and twisting on impact, offering better control when facing fast serves or aggressive loops.
  • Spin Efficiency: The weight concentration near the blade head contributes to a "whipping" effect during loops, increasing spin output with less effort.
  • Best for Distance Play: These paddles excel in mid-to-far distance play, where players have time to load into strokes and benefit from the momentum of a heavier blade.
  • Trade-offs: Reduced maneuverability and increased arm fatigue over long matches may affect players who rely on quick wrist action or close-to-table play.

Ultimately, heavyweight paddles are optimal for players who prioritize power, stability, and spin over speed of hand movement. They are especially effective in "ping pong" exchanges from a distance, where the extra mass translates into dominant offensive shots.