PondMAX PX Series High Flow Waterfall Pump is great for medium to large backyard ponds and waterfalls. The PX series features a run dry and impeller jamming protection technology to give you a long life of enjoyment. These adjustable and single speed pumps allows you to change the speed to 3 different settings. Based on your exact requirements to save energy. Adjustable speed pumps for ponds can also allow for the flexibility to provide more flow when you need to backwash a pressure filter.