The specification for this pump is as follows. Aquatec pump model # 6840-2J03-B224 24V AC. 1 Amp transformer (power supply) 110 to 120V AC to 24VAC, USA plug, Cord length about 6 feet. Pump is 3”x 4” x 7”, 6 lbs. Inlet/outlet are 1/4” quick-connect fitting for 1/4" OD tubing. Internal bypass set at 80 psi, adjustable. Heavy-duty steel baseplate with damper. It is better to put the pump on the floor. This pump assembly is designed to increase the water supply pressure to a small RO water system. Increase from 40 psi to 60 psi depending on the capacity of your RO system. This pump is for RO systems with capacity up to 75 GPD (gallons per day). This kit comes with pump (1/4” inlet/outlet) and 1 amp 24V AC power supply transformer for regular 110V USA outlet. If your water supply is from a well or the water pressure is below 50 psi, it is recommended that you add this pump kit to increase the operating pressure to about 60 to 80 psi range in order to optimize the performance of your RO system. This Aquatec 8852-2J03-B224 pump is 24V AC, the power supply is also 24VAC. Do not attach DC components to the circuit such as DC solenoid ESO, DC control box. Do not use this Aquatec 24VAC pump and 24VAC power supply to fix your broken RO systems that is non-Aquatec brand. All made in China RO systems with pumps are DC pumps and DC power supply and DC solenoid and control box. Please do not try, it will damage the circuit and it's dangerous. This listing is just pump and transformer. To make the operation automatic, you need to add pressure switch, ESO solenoid valve, or other components to control the pump. Or you can use a timer, such as Christmas light timer to turn on/off the pump at different time intervals. This 6840 pump is 1.5 LPM. If your RO system is larger capacity 100GPD to 200GPD, use bigger pump with Aquatec model: 8852-2J03-B424 All pumps are wet-tested by the manufacturer, it has water inside the pump head. Remove end plugs before use. Bypass setting is pre-set at 80 psi, to increase bypass pressure, use Allen key to turn the hex screw clockwise 1 turn. The set screw is located on the pump head. Bypass pressure is not operating pressure or boost pressure. Bypass pressure is to protect the pump from over-pressurizing. If the output is clogged or block, and/or input pressure is too high, it will limit the pressure to 80 psi. Operating pressure is the pressure after the pump. When output is open (not connecting to anything) or larger than 1.5 LPM, the operating pressure is zero. The boost pressure and operating pressure will appear when you attach a nozzle after the pump, or attach a RO membrane with flow restrictor after the pump. So the operating pressure would depend on input pressure and total output flow rate.