NorthStar NSQ Series 12V On-Demand Diaphragm Pump - 4 GPM @ 60 PSI Automatically turns off when no flow is required to conserve battery power Honeywell MICRO SWITCH for enhanced durability and efficiency Unique pressure switch design slowly cycles the pump for reduced switch and motor wear Patent-pending DXS-3 valves are made with chemical-resistant Viton for faster priming, better performance and longer life Santoprene diaphragm for reliability and longer life