Our registered brand to USPTO: Weiheng® Package:WeiHeng special package and WeiHeng LOGO stickered, please report to amazon if you receive a counterfeit copy.The best and easy way to improve your hand strength,Prevent injury, sore wrist and tennis elbow ( Lateral Epicondyle) or even get rid of it.Power up your finger, wrist, forearm, bicep etc. & Take your games into next level.It"s a very nice gift for sport lovers too Easy to start with the starting rope, thumb or even just using one hand,Six blue LED Lights will start automatically, no batteries required (Powered by a small generator embedded in the wrist ball)Max spins over 16,000 RPM (World record is already over 16,000 RPM)Intergrated computer balanced stainless steel rotor (Cheaper models only can reach 6,000 ~ 8,000 RPM, because unbalanced rotor causes too much vibration, so don"t let the lower price fool you.) Removable top cap, compatible with speed meter (Speed meter Included)Package IncludesWrist ball with speed meter x 1 Starting rope x 1 Wrist rope x 1 English Instruction x 1