U.S. Air Force Senior Airman Sean Kientz, emergency management journeyman assigned to the 18th Civil Engineer Squadron, tests a self-contained breathing apparatus during a hazardous material training exercise July 11, 2019, on Kadena Air Base, Japan. The Level A suit worn during this training provides the highest level of protection against direct and airborne chemical contact, and is often worn with a self-contained breathing apparatus. (U.S. Air Force photo by Senior Airman Cynthia Belío)