The N² cylinder is produced from high strength aluminum alloy 6061-T6. Includes a Sherwood brand GV series valve. Regulation and Inspection: All Seamless aluminum alloy compressed gas cylinders are manufactured in accordance with U.S. DOT 3AL and TC 3ALM requirements. Every cylinder is inspected and tested by a DOT and TC authorized independent inspection agency. NOTE: Cylinders have DOT approval to be filled with several gases including NITROGEN BLE Aluminum cylinder with MAXIMUM 1800 PSI rating Check if your local gas company will fill 1800 PSI Nitrogen cylinders. Capacity: 20lbs of liquid N²