Bosch's PAD auxiliary water circulation pumps feature 12-volt electronically commutated "brushless" drive motors and are designed to provide outstanding efficiency, extremely quiet operation, and long service life. The pump's stator and electronics are mechanically fully-separated from the rotor in the dry motor housing. The rotor, as part of the pump wheel, is seated in the separate pump housing. The non-contact torque transmission serves to ensure that the coolant does not come into contact with the electronics, throughout the pump's entire service life.