U.S. Air Force Senior Master Sgt. Kyle Mullen, 423rd Communications Squadron superintendent, adjusts his gas mask during training at RAF Alconbury, United Kingdom, Aug. 27, 2021. The training was designed to reinforce Airmen’s ability to properly utilize their mission-oriented positive posture, or MOPP, gear in a potential chemical environment. (U.S. Air Force photo by Senior Airman Eugene Oliver)