Staff Sgt. Ryan Duerr, 436th Security Forces Squadron combat arms instructor, teaches a class June 25, 2014 on Dover Air Force Base, Delaware. Combat Arms Training and Maintenance, or CATM, maintain all weapons for the base as well as teach airmen deploying the fundamentals and techniques of the weapons they will be using downrange. (U.S. Air Force photo/Senior Airman Jared Duhon)