NSD Power Sterling Spinner - Titan Heavyweight ZINC rotor provides 50 lbs-in torque at 10,000 RPM Strongest Aluminum Alloy shell construction made it worry-free to drop on the hard ground Enhanced Stability Control System for VIBRATION FREE operation and remarkable hand feel Ideal for building muscle and grip strength for professional and amateur athletes alike Compatible with Performance Digital LCD counter SM-02 (Battery free; displays various vital workout information )