Liberty's PC257-442-10A-EYE is a factory-assembled PC441-Series sump pump and battery backup combo system. Pairs a Model 257 (1/3 HP, cast iron) primary sump pump, wired for 115V, with a Model 442 12VDC battery backup pump — so the system keeps pumping through a power outage or primary pump failure. The two pumps are joined with 1-1/2" PVC piping and a rubber coupler for easy backup-pump service, each with its own check valve. This system's backup pump ships with a StormCell 10A charger. An audible and visual alarm signals when the backup pump runs, with a self-resetting 24-hour silence button. Fits sump pits 15" diameter x 18" deep minimum. Battery not included (works with Group 27 or 31 deep-cycle marine batteries; Liberty StormCell batteries recommended). Ships with a NightEye wireless-enabled alarm. Maximum 140°F fluid temperature. System weight approximately 42 lb.