MIL-M-87163A, MILITARY SPECIFICATION: MASK, OXYGEN, MBU 12/P (18 FEB 1983)

MIL-M-87163A, MILITARY SPECIFICATION: MASK, OXYGEN, MBU 12/P (18 FEB 1983)., This specification covers the requirements for one type of pressure-demand breathing oxygen mask, designated MBU-12/P.