Sump Pump, 1HP 3700GPH Submersible Clean/Dirty Water Pump with Automatic Float Switch for Pool, Pond, Garden, Flooded Cellar, Aquarium and Irrigation Orange. If you need the pump to work in a low water level environment (the water level does not exceed the pump), the float switch need to be locked on the pump. The working principle of the water pump is that the float switch goes down vertically, the beads inside are stuck on the line under the float switch, and the water pump starts automatically. Kindly Tip: When you start use the pump you must be submerged into the water at a slight angle to allowthe remaining air to escape. Multi Outlet Sizes: 3 different diameters outlets (1 inch, 1-1/4 inch, 1-1/2 inch) to adapte for different size hoses as needed according to the flow rate. The bigger the flow is, the wider the outlet should be. Keep Open Mode: When you put the float switch locked on the sump pump, the sump pump will keep working all the time. Once the pump can not pump any water, you should cut off the power immediately to prevent the coil from getting burned. Automatic ON/OFF Mode: The float switch should be unlocked from the pump. When the water level rises above the pump, the pump will start working automatically under the control of float switch. When the pump fails to pump water, it will automatically disconnected the power. Sealing Structure & Durable Construction: The sump pump features a durable sealing structure and the durable thermoplastic body keeps the pump from corrosion. The higher base plate which assures the prevention of debris collection in the sump pit.