Tech. Sgt. Brian Shepherd, an explosive ordnance disposal craftsman with the 1st Special Operations Civil Engineer Squadron, packs sand into a jug to mimic explosive residue from a partially detonated improvised explosive device at Hurlburt Field, Fla., Nov. 19, 2015. Wood boxes, plastic containers and backpacks are some items that can be used to make an improvised explosive device, as well as multiple types of batteries. (U.S. Air Force photo by Senior Airman Meagan Schutter)