Interstate Pneumatics WRFCO2-S CO2 Flowmeter Regulator with Solenoid Valve Electrical Solenoid valve turns on and off the flow of CO2, optimizing the usage of CO2 Self-Centering flow tube keeps ball centered to assure flow accuracy Easy-to-read 1.5 inch Pressure Gauge 0-3000 PSI with indicator of when tank needs to be refilled CGA320 Inlet, Maximum Inlet: 3000 PSIG 17 feet long black 1/4 inch tubing