Very energy efficient pumps with innovative electronics! Low noise operation. Provided with synchronous motor. No copper parts. Durable ceramic shaft. Pump stops automatically when no water is detected inside the rotor. When the impeller is blocked it will go into a “lock” position in which the pump does not use power and waits until the blockage is gone. This will prevent a motor burn out. Competitive priced dirty-water pumps for water gardens, waterfalls, fountains, filters, etc. Can pump solids up to 6mm.