1/2 HP sump pump has zinc motor housing that dissipates heat quickly and extends the pump life as well as resists corrosion. Durable cast iron base, stainless steel hardware for superior quality. Smooth Flow Hydraulics deliver high performance. Energy-efficient motor saves operating costs. Piggyback vertical float switch for manual or automatic operation in basins 10" diameter and 13" minimum depth.Performance 4,700 GPH at 0' lift; 4,200 GPH at 5' lift; 3,540 GPH at 10' lift; 2,820 GPH at 15' lift; 1,800 GPH at 20' lift.