U.S. Army Pvt. Stefan Caswell, Foxtrot Company, 1st Battalion, 210th Aviation Regiment, 128th Avn. Brigade student, trains at the Engagement Skills Trainer at Joint Base Langley-Eustis, Virginia, March 20, 2019. While Soldiers primarily train with the M4, the EST has a list of weapons units can train with. (U.S. Air Force photo by Senior Airman Tristan Biese)