El Salvadoran Air Force First Sgt. Raul Mauricio Molina Cedillos, aviation technician, speaks with U.S. Air Force Senior Master Sgt. Roberto Vasquez, 12th Air Force (Air Forces Southern) operations, plans and requirements superintendent, during a Subject Matter Expert Exchange at Davis-Monthan Air Force Base, Ariz., March 7, 2018. The SMEE focused on night vision goggles calibration, preventative maintenance and storage, and the life support structure. (U.S. Air Force photo by Staff Sgt. Angela Ruiz)