Shurflo premium delivery pump, totally sealed, 12 volt, 3.6 gpm open flow with pressure demand switch. Positive Displacement 3 Chamber Diaphragm Pump. Note: Pump is coated with a plastic compound for improved corrosion resistance. PRESSURE SWITCH: Splash-Proof, Adjustable from 30 to 50 PSI. Factory Set @ 45 PSI Shut-Off, Turn On 25 PSI 5 PSI. The Shurflo 2088 series pumps are considered the workhorse of small diaphragm pumps. They are used in a variety of transfer and dispense-on-demand applications where flows of up to 3.6 gallons per minute are required. All 2088 pumps feature self priming up to 12 feet (reduce 1 foot per 1000 foot altitude), one way check valve to prevent backflow, and automatic operation with the built in pressure demand switch.