REal C. S. 5lb CO2 Tank, Safety first, Rotating safety collar prevents a possible Valve Breakage and the Cylinder turning into a rocket., For more safety Real C. S. Double Gauge CO2 Regulator is the best High Strength Aluminum Alloy Cylinder with CGA-320 Valve, DOT Approved Cylinder for Soda kit and Draft Beer Dispensing. The tank is empty, it does not contain CO2