A service member armed with an M4 service rifle assigned to the San Francisco-based Coast Guard Port Security Unit 312 dons his M50 Joint Service General Purpose Mask while staffing an entry control point at Naval Base Port Hueneme, California, in support of Exercise Pacific Blitz 2019 (PacBlitz19), March 7, 2019. Port Security Units like the San Francisco-based PSU 312 deploy globally to provide waterborne and land-based Anti-Terrorism and Force Protection supporting Department of Defense combatant commanders. (U.S. Coast Guard photo by Petty Officer 1st Class Matthew S. Masaschi).