U.S. Army Reserve Pfc. Ricardo Ramirez (left) and Spc. Cathier Ossiri, 315th Forward Support Company, 416th Theater Engineer Command, mount an AN/PAS-13 thermal weapon sight to an M240B machine gun, Dec. 5, 2017 during Operation Cold Steel II, hosted by the 79th Theater Sustainment Command at Fort Hunter Liggett, Calif. Operation Cold Steel is America's Army Reserve's crew-served weapon qualification and validation exercise to ensure units and Soldiers are trained and ready to deploy on short notice as part of Ready Force X, bringing combat-ready and lethal firepower in support of the Army and joint partners anywhere in the world. (U.S. Army Reserve photo by Staff Sgt. Debralee Best/TF Cold Steel II)