YONEX POWERBALL TRAINING WRIST PERGELANGAN TANGAN ORIGINAL

Yonex wrist force ball men’s decompression device students use self-starting arm force grip ball wrist exercise training device

A purely artificial power mechanical device, no battery or any power source, no electromagnetic radiation, using the principle of gyro and celestial mechanics, using centrifugal force and the law of inertia to generate strong power when rotating to make the arm in motion, the user passes through the wrist The rotation to control the rhythm and intensity of the movement.