U.S. Air Force Chief Master Sgt. Jason Selman, United States Air Force in Europe-Air Forces Africa Chemical, Biological, Radiological, and Nuclear functional manager, demonstrates how to detach the drinking tube on a gas mask during a CBRN defense course on Ramstein Air Base, Germany, Sept. 24, 2020. The CBRN course teaches Airmen how to survive and operate within a CBRN contested environment. (U.S. Air Force photo by Airman 1st Class Taylor D. Slater)