MIL-PRF-83178B, PERFORMANCE SPECIFICATION: REGULATOR, OXYGEN, DILUTER-DEMAND, AUTOMATIC-PRESSURE-BREATHING, CRU-73A, GENERAL SPECIFICATION FOR (24 SEP 1999) [SUPERSEDING MIL-R-83178A]., This specification covers the general requirements for a panel mounted automatic-pressure-breathing, diluter-demand, oxygen regulator, designated CRU-73A.