Airman 1st Class Oscar Ruiz-Camacho, 28th Medical Operation Squadron bioenvironmental technician, uses a 256 kit to test air quality after a simulated chemical attack during an operational readiness exercise at Camp Lancer on Ellsworth Air Force Base, S.D., March 30, 2015. During the exercise, bioenvironmental technicians used 256 kits to simulate testing the air for chemical agents and to identify any present chemicals. (U.S. Air Force photo by Airman 1st Class Rebecca Imwalle/ Released)