Zoeller 137-0086 Model 137 Sump Pump 0.5 HP 115V 1PH 35' Cord AutomaticZoeller Model 137 Sump Pump Description Our Model BN137 Sump Pump is designed to remove unwanted water in sump or septic effluent applications. The professional grade, 1 2 HP Model 137 is known for its dependability. The BN137 is a nonautomatic pump equipped with a single piggyback float switch. The piggyback float switch allows you to set the on and off point of the pump in the field. This is ideal in an application with a deep sump pit or pump tank.