... reach over 12,000 RPM.TheoryLike gyroscopes.centrifugal force and inertia are applied.Function:1.Perfect exercise gadget for ... , wrists, hands, forearms, biceps, triceps, ligament and shoulders3. Great benefit and avoid the ligament injuries who are the typists, musicians ... watching TV, going outing and mountain climbing, and taking a bus.Features:1) The balance of the rotor has been corrected by ...