U.S. Air Force Staff Sgt. Natalia Kennedy (left), 20th Component Maintenance Squadron propulsion materials support technician, watches as Senior Airman Jade Graham (right), 20th Logistics Readiness Squadron individual protective equipment journeyman, checks the serial number on a gas mask at the Chandler Deployment Processing Center, Shaw Air Force Base, S.C., Jan. 8, 2014. Kennedy watched Graham check all of the serial numbers on each of the nine components of the gas mask before it was issued to her in preparation for an operational readiness exercise. (U.S. Air Force photo by Airman 1st Class Jensen Stidham/Released)