Handles up to 20 percent of sand, solids, leaves, and debris without clogging. Semi-vortex urethane rubber impeller with shaft mounted agitator suspends solids and allows for pumping of sand and stringy material. Continuous duty, air filled copper wound motor with class B insulation. Built-in thermal protection prevents motor failure due to overloading, accidental run-dry, and single phasing in three phase units. Double inside mechanical seals with silicon carbide faces (both top and bottom) run in an oilfilled chamber. Double shielded, permanently lubricated, high temperature C3 ball bearings rated for a B-10 life or 60,000 hours provide for extended operational life. 2 year commercial warranty.