A U.S. Marine with Marine Aircraft Group 41, 4th Marine

A U.S. Marine with Marine Aircraft Group 41, 4th Marine Aircraft Wing, puts on a M-50 joint service general purpose mask during a chemical, biological, radiological and nuclear (CBRN) individual survival skills course in support of Sentinel Edge 19 (SE19) at Canadian Forces Base Cold Lake, Canada, June 14, 2019. CBRN training test Marines abilities to respond in the event of chemical, biological, radiological or nuclear contamination. Training exercises such as SE19 ensure Reserve Marines are proficient and capable of successful integration with active-duty Marines, making Marine Forces Reserve critical to the Marine Corps’ Total Force. (U.S. Marine Corps photo by Sgt. Andy O. Martinez)