A 363rd Training Squadron munitions apprentice course instructor, center, guides another instructor as they work to build a munitions assembly conveyor at Sheppard Air Force Base, Texas, August 1, 2019. A MAC is used for convenience when a worksite may not have the right environment to set up a munitions shop. The MAC is used to create an assembly line anywhere if need be. (U.S. Air Force photo by Air Force photo by Airman 1st Class Pedro Tenorio)