100% vibrationfree and unbreakable Thanks to precise rotation during training, no annoying vibrations are created. Stability and resistance to cracking is maintained by a durable plastic housing and a robust stainless steel axle. Diodes light up the more intensely the faster the rotor rotates Characteristics: Powerball exercises are completely even, so they can complement any training method. Powerball exercises your arms in a way that conventional isotonic training (with free weights) cannot achieve, it can absorb a higher percentage of muscle fibers in less time. If you want to improve wrist, grip and shoulder strength, then the wrist exercise ball will be your perfect choice Strong Power The maximum possible rotational speed exceeds 12 000 rpm, which can generate resistance up to 32 kg. This is the best product among wrist exercise equipment slow rotation for gentle rehabilitation, or fast rotation for forearm exercises for no more than 60 seconds. Good coach Whether they play drums, piano, saxophone or guitar, musicians need to maintain strength, coordination and dexterity in their fingers and hands. Powerball helps improve agility, speed, accuracy and endurance – if you can make music, Powerball will help you play better. Specification: Name: wrist ball Material: alloy Diameter: 70mm Type: Wrist Ball Function: Muscle Relaxant Name: Powerball Wrist Ball Trainer LED Gyroscope Type: Sports Equipment Suitable for: multifunctional gym, tennis, squash, cycling and climbing Function: Family Training Gym Accessories: Yes How to use:1. Put on the lanyard attached to the ball to prevent it from accidentally dropping.2. Move the element in the center of the ball according to the arrows until further shift is impossible (resistance will occur).3. Quickly release the outer element. The builtin spring will set it in motion.4. Move your wrist rhythmically to further accelerate the ball. List of things to pack: 1 * wrist power ball 1 * Bracelet