Brand New Mira Safety CM-7M CBRN Mask with Canteen. Brand New Open Box CM-7M Mask & Canteen Size Medium. The CM-7M tactical gas mask is the ultimate chemical, biological, radiological, and nuclear (CBRN) defense system when used in conjunction with suitable filters or breathing apparatus. The military-grade technology used for this full-face respirator provides comprehensive protection against the full spectrum of CBRN agents and toxic industrial chemicals in the form of gases, vapors, and aerosols.