USAF Airmen from the 13th Aircraft Maintenance Unit don Mission Oriented Protective Posture (MOPP) gear in a hangar and perform maintenance on a 13th Fighter Squadron F-16 at Osan Air Base, Republic of Korea.

MOPP is a protective gear used by military personnel in a toxic environment, e.g., during a chemical, biological, radiological, or nuclear (CBRN) strike. (read more: en.wikipedia.org/wiki/MOPP)