Product Description:Name: Powerball Wrist Ball Trainer GyroscopeAutomatic startType : Wrist ballMaterial: PC, aluminum alloy, silicone rubberSuitable for: home workouts, exercise,tennis,cycling and rock climbingFEATURES:Small, compact and transportable, you can take anywhere. Simple to start with a pull-string.And we have a flashing LEDstyle,all you need do is to increase the speed by making a rotational wrist movement and to keep in sync with the spinning ofthe ball.This certainly requires some fine motor skills in order to use it. The dominant hand/arm was easily able to keep the gyroball going, that it will help refine you're fine motor skills in that non-dominant hand/arm.Make Arm Great Again. Strengthen fingers, wrists, hands, forearms, shoulders, and bicep, etc. It also can be beneficial inpromoting co-ordination and blood circulation.Package included: 1x Gyroscopic Powerball