Fully Submersible Back Up Pump, for An Easy Addition To Any Sump System ALL Cast Iron Construction for Long Life in Tough Sump Applications Corrosion-Resistant Thermoplastic Impeller for Maximum Water Flow Protective Battery Case Included with LED Display and Audible Alarm to Let Homeowner Know Theres a Problem 1-1/2 in. NPT Discharge for Easy Installation and Compliance with Building Codes For Use In 14 in. Diameter or Larger Sump Basins