JIN BDWrist Trainer Ball Auto-Start Wrist Strengthener Gyroscopic Forearm Exerciser Gyro Ball for Strengthen Arms, Fingers, Wrist Bones and Muscles?Blue Without Light?

Features

• 【Self-starting design】The movement in the ball comes with a spring starting device, no power supply and no rope. Gently press the inner ball with both thumbs and wind it fully in the direction of the arrow. Then, you can easily start the ball by rotating your wrist in a single hand.
• 【Power control】After the gyro ball is started, the speed of the wrist movement varies to produce different training forces. Increase the fun of exercise.
• 【Mechanical power lasting】 The centrifugal force generated by the interaction between the rotation of the wrist and the inner rotating ball core maintains the high-speed and lasting operation of the ball core.
• 【Light and portable】The moderate size and weight are easy to carry around, whether it is the office, the gym, home or travel, you can easily exercise and decompress at any time.
• 【Assisted rehabilitation】Wrist ball training can promote blood circulation, increase the strength of fingers, wrists, palms, forearms, biceps, triceps and ligaments, shoulders, and restore muscle strength.