24.1 cubic foot medical oxygen tank with CGA870 post valve installed. Ready to perform in EMS, home oxygen, and hospital use. Cast from a special alloy that's extra resistant to corrosion, fractures, and damage for the utmost in safety and durability. Light, strong, and built to the highest standards of testing and quality Brushed finish and green painted dome, in non-sparking aluminum. Meets U.S. Department of Transportation (DOT) specifications. Doctor's prescription required to fill with medical oxygen. Seek the advice of a physician if you have questions about the proper use of medical oxygen. Please be sure to use a regulator that fits the cylinder valve, and that is correct for your application of use. Product note: compressed gas cylinders can be dangerous if used improperly. Please be careful, know the correct procedures for use, and exercise caution when connecting and using any compressed gas device.