TopSpin Whistle A simple adidas essential trusted

A simple adidas essential trusted by players at every level

Pro X is the firmest

Sync provides optimal pocketing allowing you to dictate with pin-point control and precision

Maximize your tennis with ReString Zero

If you're already a Solstice Black convert

TopSpin Whistle A simple adidas essential trustedThe TopSpin Whistle: Instant Feedback for a Heavier Ball Stop guessing if youre getting enough "brush" on the ball. The Spin Whistle is a simple, racket mounted tool that gives you a clear audio cue the moment you hit the correct swing path. How it works: If you hear the whistle, youve nailed the acceleration. If its silent, youre not hitting with topspin. Its that simple. By turning your technique into sound, you can fix your swing in real time.