The Airdog A4SPBF170 100 GPH Fuel System is a diesel lift pump that replaces your factory low pressure frame rail mounted fuel pump. This system mounts to the frame rail using the supplied sandwich plate mounting system. Fuel is picked up through the factory suction line, in the fuel module, to feed the AirDog. The pressure side connects directly to the factory injection pump feed line on the frame. The AirDog Air/Vapor return is sent back to the tank through a filler neck tee. This is a 100GPH (Gallon Per Hour) lift pump system.