The Rim Drive is unique in its design when operating this unit is virtually silent. The propeller forms the rotating part of the electric motor (Rotor) and the fixed winding (stator) is mounted in the tunnel. Therefore no noisy gears are used in this design. Secondly, a ring mounted around the propeller prevents the propeller from cavitating. This unit comes proportional controlled, with virtually unlimited run time, unlike traditional thrusters which have typically have a run time of 3-5 minutes. Lock the thruster at any speed and hold the boat alongside the dock. Can be used as a stern thruster as well. Call us today for more information and pricing. This is the latest thruster technology out to date and supplies are limited.