NSD Power Winners LED Spinner Gyroscopic Wrist and Forearm Exerciser Featuring Advanced LED Matrix Counter Display, Blue LED Matrix counter built into rotor displays highest speed in RPM and 30 second Physical Strength Index right on the surface of the rotor; Certified for entry into our Monthly Top Speed Contest; See our Facebook page for more information Computer balanced inner gyroscopic rotor for VIBRATION FREE operation at up to 15,000 RPM Hard, impact resistant plastic shell that comes in an attractive BLUE with exclusive BLACK rotors Simple to start with a pull-string (included); Reversible inner tracks make 2X Lifespan Small, compact exercise machine you can take ANYWHERE; Provides up to 23.7 pound-in of torque at 10,000 RPM