Col. Eric J. Steidl, 22nd Marine Expeditionary Unit commanding officer, and Denver native, drinks from a canteen using the drinking tube attached to the newly issued M-50 field protective mask during the MEU's annual gas-chamber training aboard Camp Lejeune, N.C., Aug. 27, 2010. The M-50's improved drinking system allows better water flow than its predecessor the M-40. The MEU was the first major subordinate command in the Marine Corps on the east coast to receive the new M-50 gas mask for training. The training is designed to instill confidence in the mask and ensure the Marines know the proper wear of the equipment.