What sleeve device would indicate an officer of rank O-4?

An officer of rank O-4 corresponds to the rank of Major in the U.S. Army, Air Force, and Marine Corps, and Lieutenant Commander in the Navy. The insignia worn on the sleeve for this rank consists of two half-inch gold stripes with an additional quarter-inch gold stripe in between. This specific arrangement of stripes is designed to visually differentiate the rank from others. The two half-inch stripes represent the higher officer's rank, while the quarter-inch stripe serves as a distinguishing mark, signifying that the officer is at the O-4 level.

The other options do not accurately reflect this rank: a single two-inch gold bar typically represents O-3 (Captain), while three half-inch gold stripes denote O-5 (Lieutenant Colonel or Commander), making them incorrect representations for the O-4 rank. The correct arrangement of two half-inch gold stripes with a separate quarter-inch stripe in between is crucial for proper identification and recognition of rank within military structures.