Using a Gyroscope Force Wrist Exercise Ball is the most effective and convenient device to increase muscle strength in your arm, wrist and hand.
This tennis ball size gadget works via a ball within a ball system creating immense gyroscopic force, with speeds recorded of up to 15,000 rpm and generating a force of up to 40lbs. No batteries required, just wind the thread around the ball and pull briskly to get the ball in motion. Then twist the ball to get it spinning faster, the faster it spins the brighter the built-in light and stronger the forces get.
Ball size: Appx 7.5cm
• Wrist Exercise Ball that will help iIncrease the muscle strength in your arm
• Spins at up to 15,000 rpm generating up to 40lbs of gyroscopic force
• No batteries required