Exercise participant from the 19th Airlift Wing receive a briefing on radiological protection procedures during phase II of ROCKI 20-01 at Little Rock Air Force Base, Arkansas, Nov. 15, 2015. Phase II is divided into two sub-phases: phase IIa stresses Airmen’s ability to survive and operate in a simulated chemical environment; phase IIb stresses their ability to survive and operate in a simulated radiological environment. (U.S. Air Force photo by Senior Airman Kristine M. Gruwell)