U.S. Marine Corps Sgt. James R. Hochstetler, an instructor with Weapons and Field Training Battalion, explains how to assemble a gas mask Nov. 14, 2017, on Parris Island, S.C. Field training instructors, like Hochstetler, 24, from Manchester, Va., are responsible for teaching recruits how to use the gas mask and ensuring they can properly put the mask on while inside the gas chamber. Fox and Oscar Company are scheduled to graduate Jan. 5, 2018. Parris Island has been the site of Marine Corps recruit training since Nov. 1, 1915. Today, approximately 19,000 recruits come to Parris Island annually for the chance to become United States Marines by enduring 12 weeks of rigorous, transformative training. Parris Island is home to entry-level enlisted training for approximately 49 percent of male recruits and 100 percent of female recruits in the Marine Corps. (U.S. Marine Corps photo by Cpl. Joseph Jacob)