The Liberty PC257-441 Sump Pump Combo Series is a pre-assembled primary pump and battery back-up system. It assures continuous pumping should there be a power outage or main pump failure. An audible and a visual alarm gives a signal that the back-up pump will start operating. It includes a primary pump, a back-up pump, a 1-1/2" PVC piping, and a check valve for both the primary and back-up pump. This Liberty PC257-441 Sump Pump Combo Series has a primary pump that can handle temperatures of up to 140˚ F. It has a discharge size of 1-1/2". It can pump up to 50 GPM at 0' head pressure and has a shut-off head of 23'. It has a 1/3 hp motor. The voltage needed to run this pump is 115V single phase. The back-up pump can pump up to 45 GPM at 0' head pressure. It uses a 5-stage battery charging which features a protection from battery burn-out. More details are available in the specification sheets. The Liberty PC257-441 Sump Pump Combo Series is covered by a standard Limited Warranty for a period of 3 years. This product proudly bears the CSA mark and is recognized for meeting the required environmental performance standards. Liberty, the company that makes and innovates high quality pumps is relied on by hundreds of professional contractors each day. Liberty has been cited as one of Rochester's Top 100 Companies for twelve years.