5-pound aluminum CO2 cylinder. Looking to serve your homebrew on draft? This CO2 tank is the perfect size for homebrew draft systems. Manufactured from high strength aluminum alloy 6061-T6. 18 1/4" h x 5 1/4" diameter. Service Pressure: 1800 psi / 124 bar Specification: DOT-3AL & TC-3ALM designed. Shipped empty.