Zoeller 137-0050 Model 137 Sump Pump 0.5 HP 460V 3PH 10' Cord NonautomaticZoeller Model 137 Sump Pump Description Our Model G137 Sump Pump is an all cast iron pump designed to remove unwanted groundwater in basement sump applications. The professional grade, 1 2 HP M137 is great option when a high flow cast iron sump pump is required. Known as the Flow Mate, the G137 is a fully automatic float operated sump pump. The white polypropylene float is solid so it cannot become waterlogged. This ensures that it is always buoyant