军用背包厂家U.S. Army Rangers, assigned to Delta Company, 3rd Battalion, 75th Ranger Regiment, dismount Strykers during a training exercise on Fort Knox, Ky., April 24, 2014. The 3rd Battalion is undergoing annual task force training to evaluate how their Soldiers perform during operational situations. Rangers are constantly training to maintain the highest level of tactical proficiency. (U.S. Army Photo by Pfc. Gabriel Segura/Released)