24.1 cubic foot medical oxygen tank with CGA870 toggle 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 safety and durability. Light, strong, and built to the highest standards of testing and with a green painted dome, in non-sparking aluminum. Meets U.S. Department of Transportation (DOT) specifications. A doctor's prescription is 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.