The ProLeaf Regulator is controlled by the Pro-Leaf CO2 Controller. It can be attached to a CO2 bottle and the controller will turn it on or off to increase the CO2 to your desired set point. Coupled to the Pro-Leaf controller this regulator is maintenance free and there is no way it can freeze open like many other regulators on the market. Simple to use Constructed from solid brass Two pressure dials: (1) gas pressure and (2) flow rate. Hose tail: suitable for 4.2mm inside diameter hose with solenoid value and USA standard plug Features heavy-duty solenoid value. High quality oil-less pressure gauge. Includes two plastic tank washers and 12 ft. of CO2 dispensing line. Brass construction for long-lasting dependability and durability. 1Amp/120 Volts/60Hz