TwinPower Turbine handpieces feature the world's only double-impeller rotor design. This unique innovation delivers superior cutting power even under high load conditions. TwinPower also offers the world s only zero drawback feature. A pressurized air system prevents the intake of contaminated aerosol and other particles into the air line - a first for the dental industry. This feature helps eliminate cross contamination of the handpiece, coupling, air line, and treatment unit.