MIL-PRF-83178C, PERFORMANCE SPECIFICATION: REGULATOR, OXYGEN, DILUTER-DEMAND, AUTOMATIC-PRESSURE-BREATHING, CRU-73A, GENERAL SPECIFICATION FOR (18 MAY 2009) [SUPERSEDING MIL-R-83178A]., This specification covers the general requirements for a panel mounted automatic-pressure-breathing, diluter-demand, oxygen regulator, designated CRU-73A.