Stock Photo Description: Free, public domain image: Person Wearing a Gas Mask.
Staff Sgt. Christopher McFefries takes a break June 23 during the 2009 Chemical, Biological, Radiological, and Nuclear Challenge at Ramstein Air Base, Germany. The CBRN Challenge consisted of six base teams going head to head in six different scenarios, an equipment olympic challenge, and land navigation challenge. Sergeant McFefries is a 100th Civil Engineer Squadron emergency manager. (U.S. Air Force photo/Staff Sgt. Stephen J. Otero.
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