The 257 Liberty Pump is a 1/3 HP Automatic Submersible Sump Pump that is magnetically operated with a vertical float VMF switch and 10ft power cord. It is a unique one-piece cast iron housing and thermally protected & permanently lubricated motor.This pump can operate in a 10" diameter sump pit, handles solids up to 1/2", and has a 18' shut-off head. Model 257 is for Sump and De-watering Applications only. This Vertical Magnetic Float (VMF) model is not recommended for effluent applications due to their short On/Off cycle. Wide angle float models such as Liberty Pumps 251 and 253 are better suited for effluent applications and are easily adjustable for different On/Off levels.