huaker wrist trainer ball auto-start excerises arm strengthener essential gyroscopic wrist and forearm exerciser wrist ball for stronger muscle and bones workout huaker <br><b>what is the wrist ball</b> <br>the wrist ball is the fastest artificial power device in the world. <br>it is purely mechanical, does not use batteries and any power supply, has no electromagnetic radiation, and rotates the core at a high speed by the rotation of the wrist, thereby generating wrist ball. <br>through artificial control, the rhythm and speed of the core rotation can be adjusted arbitrarily. <br>the faster the speed, the greater the force generated. it can be equivalent to 50 dumbbells of different weights. <br>there are about 14kg of force at 8000 rpm, and about 22kg at 10,000 rpm. power. the world record has exceeded 20,000 rpm. <br>because of generated by high-speed rotation, it is very helpful to exercise the strength and toughness of fingers, wrists and arms. <br>it combines sports, entertainment and fitness into one, and is increasingly favored and loved by people all over the world. <br> <br><b>features:</b> <br>type: wrist ball <br>function: muscle relax apparatus <br>applicable scene: wrist fitness <br>texture of material: pc <br>size: 2.83x2.32inch <br>net weight: about 250g <br> <br><b>how to start it</b> <br>1. toggle the ball along the double direction arrow to the max resistance,then release it,fast enough to have the ball turn the led on. <br>2. turn your plam facing down, and slowly start to rotate, you will feel that it is scratching against the inside of the wrist ball. <br>3. keep rotating with wrist then the ball will spin faster, develop a higher pitch sound. once you feel it spinning fast enough, stop your rotate, you could feel it oscillating right in your palm. <br><b>tips :</b> <br>do not touch the ball rotor when it is spinning at high speeds,it will burn. <br>not suitable for children under 10 years old whose hand strength insufficient to use the product <br>do not add any oil or moothy liquid into it which may cause it inoperation