Petty Officer 3rd Class Collins Scheffer, Naval Mobile Construction Battalion 133 heavy equipment operator, left, talks to Petty Officer 2nd Class Christian Rivera, NMCB 22 heavy equipment operator, while operating a grader during construction of a parking pad at a Djibouti airfield, July 28, 2016. The grader is used to evenly spread gravel to a three-inch height during construction. (U.S. Air Force photo by Staff Sgt. Benjamin Raughton/Released)