YUNMAI LED Wrist Trainer Ball, Black With the novel design of LED lights, you can see how fast the rotation speed is. When rotating, the LED lights up. The faster the rotation, the brighter the LED light, as long as it rotates, it will remain lit, set sports, fun, fitness in one,The light will only illuminate when your speed is fast enough. More Suitable for Sports Training, Wrist Workout - Highly beneficial grip strength trainer. You only need to push the core in the direction of the arrow, Push it to the top, then quickly release it and rotate your wrist so that your wrist rotates with the rotation of the core. The centrifugal force of the core can easily start the gyroscope ball. it will make you feel incredible when the gyro ball starts to spin in your hand. The unit did not have any weird vibration to it. Also having the silicone grip section is very nice as it helps with the gyro ball not coming loose from your hand. Features: • Multifunctional design can be used in office, gym or home, and also can be a good pressure reducer as well as a good toy and arm muscle exercising • Smart gravity sensor can be used to feel the centrifugal force and to strengthen your limbs coordination or rehabilitation training • Simple operation can be powered on quickly by rotating your wrist to make fast speed • Compact size can be put in your bags to do outdoor activities • High-quality zinc alloy and plastic materials, durable and non-toxic • Stylish look with a quiet sound can be a great gift • The colorful flashing version is limited to the black version of the wrist ball. Specifications: Brand: Yunmai Product name: Wrist Training Ball Model: YMGB-Z701 Weight: 270g Material: Polycarbonate, Zinc Alloy Color: Black, Blue, Red Size: 70 x 70 x 55mm Package included: 1 x Wrist ball - Black 1 x Wrist strap 1 x Manual