... electrical protecting controller device, against under-voltage, over-voltage,over-flow, overload, waterless , automatic recovery ,controlling water height as demand.2 ... , maintenance-free, safe and reliable. Water depth :1-180m ,Max flow: 2.6m³/h.3. Adopt stainless steel screw and rubber ... head and must be immersed in water. NEWSKY Noiseless Screw Low Flow High Head 3SPS DC Solar Water Pump