Mounting on whichever side of the racquet works fine.

Yes, we have tested our sensor with ex-pro tennis players, tennis coaches and also club players for the past few years.

The sensor would not be damaged. However, there is a possibility that your readings might be off for that particular stroke.

Using the sensor in rain is not recommended as our sensor is not water proof.

QLIPPTM sensor has a detection range of 40m- 50m (whole court). It will be fine as long as your phone and the sensor is within a court distance.

QLIPP uses the racket head speed to derive the estimated ball speed.

No, they would not affect the sensor and its readings as our motion analytics have already accommodated for such differences.


– Topspin, slice,flat


– Topspin, slice,flat


– Topspin, flat

Apart from being one of the lightest in the market, the QLIPP Ultimate Tennis Performance Sensor can also be attached to any racquet with its registered “twist and lock” technology. It provides a dampening effect as well.


– Lightest tennis performance sensor at 8g
– Only sensor that allows you to easily attach to any tennis racket with a registered twist and lock design
– Doubles as a dampener
– Record, playback and review every stroke in slow motion


– Real-time feedback with voice control options
– Analyze your game: Record every stroke and see detailed stats of your topspin, speed and sweet spot accuracy for every session
– Save your stats to review your progress


– See how your stats match up in the QLIPP™ community leaderboards
– Organize matches with other players
– Share your progress on social media

QLIPPTM, the Ultimate Tennis Performance Sensor, is the lightest most portable tennis sensor in the market to date. Its patent pending technology offers measurements and video capture of your strokes, spin, speed and sweet spot accuracy. Data is wirelessly transferred and displayed in real time on the QLIPPTM app, which will be available for both iPhone and Android devices. Save each session for future reference, or compare your performance with friends’.


Mobile App

Yes, videos can be exported via iTunes. In iTunes, go to Apps, under file sharing, choose QLIPP. From there, you can copy the videos to your PC.

No. After you have selected whether you are a right or left hander, our sensor is able to differentiate your serves, forehands and backhands automatically by measuring the corresponding vibrations of each type of stroke.


– iPhone 4S to iPhone 6S
– iPad Retina to iPad 4
– iPad Mini
– iPad Air to iPad Air 2.

Andriod (Most devices running Android 4.3 Jellybean with Bluetooth 4.0)

– Samsung S4 and above
– Google Nexus 4 and 5

– Stroke by stroke breakdown into speed, sweet spot and spin
– Session overview, including the best stats and your average performance for that session
– Video recording with slow-motion playback, along with the accompanying stats for every stroke
– QLIPP Community – For you to share your data and videos with like-minded tennis players and also to track your progress.

No, the mobile application can be downloaded for free with each purchase of our QLIPP sensor.


Metric Calculations

The estimated ball speed (KM/H or MPH) derived using the racquet head speed. The actual ball speed may vary depending on racquet, string tension and weather conditions.

A value(0 to 100) to represent the amount of spin imparted onto the ball in your topspin/slice strokes. Revolutions Per Minute(RPM) is NOT used as it can vary a lot depending on string / spacing of racquet used.
0:No Spin
100:Maximum spin detectable

A value(0 to 100) representing the estimated location of where on the racquet the ball has impacted, with reference to the sweet spot.
0: Racquet Frame
100: Sweet spot (NOT necessarily the center of the racquet)

The QLIPP Score is a value (0 to 100) obtained through the average of your ground stroke stats: speed, sweetspot and spin.


A service is separated into 3 states; ‘Racquet Preparation’, ‘Racquet Acceleration’ and ‘Follow Through’. In general, the time spent in each state should be in the ratio of 4 : 2 : 5.
For example:Racquet Prep.:400ms, Acceleration:200ms, Follow Through:500ms

Racquet preparation BEFORE the service stroke.
Professional Timing: 140ms to 180ms

Time spent accelerating the racquet AFTER the racquet preparation and BEFORE the impact of the ball on the racquet.
Professional Timing: 70ms to 90ms

Follow through swing AFTER the impact of the ball on the racquet.
Professional Timing: 180ms to 250ms

The angle of the racquet when it hits the ball. Hitting at the Peak will result in a higher ball speed than Before or After.

The Form is a score (0 to 10) obtained by comparing your service stroke with that of a professional player.
0: Bad 10:Good

For speed, there will be in both mph and kph. Unfortunately for spin, there won’t be Rpm measurement for now as we will be using the standards and statistics from a pro-athlete as our benchmark.

Technical Information


– iPad 3 and above (including iPad Mini, iPad Retina, iPad 4, iPad Air, iPad Air 2)
– iPhone 4S and above

Andriod (Most devices running Android 4.3 Jellybean with Bluetooth 4.0)

– Samsung S4 and above
– Google Nexus 4 and 5

Connectivity: Bluetooth 4.0 Low Energy
Connection range: 50m (164ft) line of sight in open air
Operating time: At least 4 hours at 25°C (77°F)
Battery cycle: 500 times
Charging time: Maximum 1.5 hours
Operating temperature range: 0° to 60°C (32° to 140°F)
Charging temperature range: 0° to 45°C (32° to 113°F)
Storage temperature range: -20° to 60°C (-4° to 140°F)
Weight: 8g (0.28oz)
Dimensions Length: 29.55mm (1.16in)
Width: 25.66mm (1.01in)
Height: 14.74mm (0.58in)
Approvals: Pending
Warranty: 1 year limited warranty

Sensor Information

It takes about 90 minutes to charge the sensor from 0% to 100% charged.

When Charging
Blue solid – Fully charged
Red solid – Charging

When Not Charging
No LED – Sensor is powered off

Blue solid – Waiting for Qlipp Tennis app to connect
Blue blinking (2 short flashes and 1 long pause) – Connected

Red solid – Waiting for Qlipp Tennis app to connect, but low battery
Red blinking (2 short flashes and 1 long pause) – Connected, but low battery
Red slow flash (1 long flash and 1 long pause) – Unexpectedly disconnected from device (usually due to out of range)

The battery is able to last for 4-6 hours per charge.


If the device is on Android 6 and above, you need to enable Location Permission. To do so,
Go to Settings -> Applications -> Qlipp Tennis -> Permissions -> Location Permission set to YES.

Make sure that your location service is also switched on. This is because we are using Bluetooth Low Energy(BLE) to connect to the sensor and Coarse Location Permission is required. However, please be assured that location information is not accessed by our app.


Contact us at freedom@degrees9.com for regulatory information.

9 Degrees Freedom was established in 2012 and the QLIPP sensor has been in constant development for the past 2.5 years.