Lance Cpl. Jesus Monroy, M1A1 tank crewman with Company A, 4th Tank Battalion, 4th Marine Division, Marine Forces Reserve, listens to communications in the driver seat of a M1A1 Abrams Main Battle Tank during his annual training at Marine Corps Base Camp Pendleton, Calif., July 19, 2016. Marines fired the tanks to adjust their battle sight to zero before the main event of their annual training. The main event includes 36 hours of offensive and defensive operations where 4th Tanks will be engaging with a notional enemy with a company of 14 tanks. This is the first time in over a decade tanks have fired main gun rounds on Camp Pendleton.