Active Air 20 lb CO2 TankEnrich your indoor grow environment for increased yield with CO2 Tank. It is designed to supply a huge amount of carbon dioxide in a portable and safe container. It has a compact design that wont consume much space in your grow space. This CO2 cylinder is made from high quality aluminum alloy that guarantees a long life span. Moreover, this CO2 tank caters to TC 3 ALM and U. S. DOT 3 AL requirements. It is well tested by the TC and DOT sanctioned