Coollang Tennis Racket Sensor Tracker Motion Detector Analyzer with Bluetooth 4.0 Compatible with Android and iOS Smart Phone

This is absolutely terrible. the sensor is too wide so it is uncomfortable to use while playing tennis. the flex adaptor is terrible, it is a complete no go, the stickers work but you cant move between racquets.The sensor does not measure sweet spot or spin and the speed estimations are way off.What really ticked me off was the App. It is embarrasing. the video recording does not work with my iphone 8. the connection breaks in the middle of the session so only off line recording works. Offline recording just offers a summary instead of shot by shot analysis and the summary does not differentiate shots properly. for some reason it thinks most shots are sliced backhands (which I barely use).It is a joke. Please dont waste your money like I did

The product is awesome. I am just starting to use but I am sure it will help me to improve my way of playing tennis. Product well designed and with nice packing. Just stated to analyze the software but it seems very nice. This was one of my best buy in Amazon. I do recommend to the onde that loves playing tennis.

Hola!!! Abro el app y alMomento de abrirla se cierra sola, y no me da oportunidad de usarla... que puedo hacer ?