Patented Design; Compatible With Nsd Digital Speedometer Sm-01 * 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 color: Amber * Simple to start with a pull-string (included), see video for tips and tricks * Small, compact exercise machine you can take ANYWHERE. Provides up to 26.8 lbs.-in of torque at 10,000 RPM