These disposable (single-use) prophy angles have a 120° reciprocating motion which prevents muzzle hair from wrapping around the cup and allows for continuous-contact polishing. Some of the Twist's other features include:
Robust gear mechanism provides a smooth, continuous motion
Recessed grip enhances the ergonomics of the angle providing a secure and comfortable grasp
Smaller head improves visibility and increases maneuverability
Enhanced cup fluting improves interproximal application 
