Senior Airman Ants Vahk (right), 92nd Aerospace Medicine Squadron bioenvironmental engineer, sizes Staff Sgt. William Anderson (left), 92nd Maintenance Squadron munitions systems technician, with a sizing tool Dec. 7, 2016 at Fairchild Air Force Base, Washington. The sizing tool gives an estimation on what size mask a person should wear. (U.S. Air Force photo/Senior Airman Nick J. Daniello)