U.S. Air Force Staff Sgt. Michelle King, the emergency manager for the 127th Civil Engineer Squadron, Michigan Air National Guard, wears the new M50 joint service general purpose mask Dec. 1, 2011, at Selfridge Air National Guard Base, Mich. The mask was designed as an improvement over previous gas masks by having a lighter weight, a larger field of vision, 24 hours of chemical and biological agent protection and other features. Distribution for the mask was scheduled to begin at the January 2012 unit training assembly at Selfridge for Airmen with the 127th Wing.