 The U.S. Marines with 5th Air Naval Gunfire Liaison Company, three Marine Expeditionary Force Information Group, conduct a foot movement under load in preparation for cross-country combat maneuver in chemical, biological, radiological and nuclear defense training on Camp Hanson, Okinawa, Japan, January 25, 2024. The gas chamber training, which is an annual requirement, consists of Marines being exposed to chlorobenzal melonitral tablets, commonly known as CS gas, to familiarize themselves with their M-50 gas mask. The U.S. Marines with 5th Air Naval Gunfire Liaison Company, three Marine Expeditionary Force Information Group, conduct a foot movement under load in preparation for cross-country combat maneuver in chemical, biological, radiological and nuclear defense training on Camp Hanson, Okinawa, Japan, January 25, 2024.