U.S. Army Command Sgt. Maj. John Wayne Troxell, Senior Advisor to the Chairman of the Joint Chiefs of Staff (left), coins U.S. Air Force Airman 1st Class Jonathan Michaels, 325th Maintenance Squadron Weapon Standardization Evaluation Program Precision Guided Munitions technician (center), during his visit to 325th MXS Weapon Standardization Evaluation Program Precision Guided Munitions Section at Tyndall Air Force Base, Fla., April 23, 2018. Presenting military personnel “challenge coins” is an honored military tradition with the purpose of acknowledging exemplary service or dedication to duty. (U.S. Air Force photo by Airman 1st Class Solomon Cook/Released)