PETERSON AIR FORCE BASE, Colo. -- Col. Kirsten Aguilar (left), 21st Mission Support Group commander, presents the guidon to Lt. Col. Timothy Fryar (right), the new 21st Civil Engineer Squadron commander, during a change of command ceremony June 27, 2019 at Peterson Air Force Base, Colorado. The passing of the guidon represents a formal transfer of authority and responsibility from an outgoing commander to an incoming one, ensuring that the unit and its Airmen are never without leadership. (U.S. Air Force photo by Airman 1st Class Andrew J. Bertain)