These water-powered back-up sump pumps use the flow from a municipal water system to provide enough power for additional hours of flood protection in case of power loss or primary pump failure. They eliminate the need to check, maintain, and replace batteries in battery-powered back-up systems. Pumps are not for use with electric-powered water well systems since a power outage will shut down the well pump and the water flow that powers the backup pump. This listing is for each.