MIL-PRF-27210G (AMENDMENT 1), PERFORMANCE SPECIFICATION, OXYGEN, AVIATOR'S BREATHING, LIQUID AND GAS (24 JAN 2000) [SUPERSEDING MIL-O-27210F]., This amendment forms a part of MIL-PRF-27210G, dated 4 April 1997, and is approved for use by the Departments and Agencies of the Department of Defense.