With the exception of enlisted airmen assigned to the Air Force Band and the Air Force Base Honor Guard, each of which has its own distinctive cap insignia and other uniform devices, Air Force combination caps bear a relief of the Great Seal of the United States rendered in silver-colored metal. For enlisted members, the arms are surrounded by a silver-colored metal circle. (The Chief Master Sergeant of the Air Force has a wreath instead of the circle). Commissioned officers' insignia is larger and lacks the encompassing circle.