In/Out
Tech specs 
Dimensions45mm x 90 mm x 75 mm (H x W x D)
Weight
Battery lifeup to 2 hours. You can extend this with a portable battery.
Water resistanceSplashproof
Internal memory4GB. Upgradable via SD card.
DisplayYes
SensorsAccelerometer, two cameras
Smart watch compatible
Removable
Compatible brandsAttaches to any tennis net post in seconds. Ready-to-use with the court auto-calibration (automatically detects lines). Essentially functions like a hawk-eye system.
Metrics 
Power
SpinYes
Impact location
Number of shots
Shot type
Spin type
Swing speed
Ball speedYes
Live trackingYes
Video function1080p video recording for each half-court (Live mode or SD card standalone). HD video features an augmented reality overlay.
Other- Real-time light and sound to signal if the ball is in or out
- Stats analysis, just like for the pros (distance covered by players and their depth position are calculated in real time).
- Shot placement with percentage by zone as seen on TV is calculated for both players. Additionally, shot height and position can be optionally obtained.
Links 
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Amazon US rating
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