U.S. Marine Corps Lance Cpl. Steven Maldonado, right, a radio operator with Communications Company, Headquarters and Service Battalion, 3rd Marine Division, III Marine Expeditionary Force, explains the PRC-117 and its compatibility with the secure communication controller in the combined operations center during Marine Expeditionary Force Exercise (MEFEX) 2014 at Daegu Air Base, South Korea, March 12, 2014. MEFEX 2014 was a U.S. Marine Corps Forces Pacific-sponsored series of exercises between the U.S. Navy and Marine Corps and South Korean forces. Among the exercises were the Korea Marine Exercise Program, Freedom Banner 14, Ssang Yong 14, Key Resolve 14 and Combined Marine Component Command 14 command post exercise.