U.S. Air Force Senior Airman Kevin Holley, 7th Aircraft Maintenance Squadron aircraft electrical and environmental systems specialist, writes the tail number of a B-1B Lancer on a mason jar at Dyess Air Force Base, Texas. The mason jars are used to collect samples of oil from the aircraft in order to test for contaminants. (U.S. Air Force photo by Senior Airman Kedesha Pennant)