Chinese PLA Gas Mask Type 64B, dated January 1980. Filter is not original, but a modern Z-A-P3-3 (A3P3) Orcanic Vapor/Aerosol Filter dated October 24, 2018. Honestly one of my most comfortable ComBloc
3M™ Filters for Face Masks - A1 / A2 / ABEK1 / P2 / P3 | Rapid Online
Combined filter drier and receiver Type DCC and DMC - Winnovation