The inlet side of the holding tank and will shut-off the pump when the tank is full. The 2' wiring harness (included) interconnects to the pump and transformer. Factory preset to shut-off at 60 PSI, and turn on at 25 PSI. Additional Details ------------------------------ Product description: The inlet side of the holding tank and will shut-off the pump when the tank is full. The 2' wiring harness (included) interconnects to the pump and transformer. Factory preset to shut-off at 60 PSI, and turn on at 25 PSI.