Powerball 250Hz Pro Autostart Lights Counter It exerts a force of up to 20 kg Maximum speed approx. 15,000 rpm Perfect for people actively practicing sports It improves the strength of the wrist, e.g. for long hanging on a rock ledge, but also useful in tennis, golf, squash, etc. Rev counter with buttons Automatic start LED powerball backlight Color: black Dimensions: 7.5cm x 6.5 cm One of the fastest motorless machines in the world! The Powerball is a good toy, but mostly a training device. Perfectly strengthens the strength of forearms, wrists, fingers and grip. Although it's actually great for office tournaments - it will just show who is the strongest and fastest. In simple words, when it comes to speed, our 250Hz model is the undisputed leader. In this model, the gyroscope is in no way limited by the inductive dynamos built into the rotors of the Neon and Techno models and thus accelerates to the highest speeds. The device works as a combination of an internal gyro, centrifugal force and inertia. After accelerating the inner ball, continue to rotate the entire device with your wrist to increase the speed of rotation. Apparently, you can get up to 15,000. revolutions per minute (the world record is over 16,000! ). Your wrist will feel a great force from the rotating device, after the first use, the hand tremors are almost certain. At 15,000 revolutions, the force of approx. 20 kg! The built-in computer shows the current revolutions and the most recent fastest revolutions (record). For some, breaking the record is the goal of play, the side effect of which is a stronger wrist and grip. Stop the rubber wheel and switch to Powerball, you won't regret it.