A gold color metal and enamel device 1 1/8 inches (2.86 cm) in height overall consisting of a gold vertical sword enflamed red with hilt to base behind a gold stylized Philippine sun bearing a red annulet issuing dual parallel rays saltirewise, all within two gold sea lions at each side, facing out and reverse to one another, tails looped and curved to base conjoining with the ends of three horizontal wavy blue bars, and paws grasping a red scroll arced across the top bearing the inscription "GUARDIAN OF THE FLAME" in gold letters.
Crimson and light blue are the colors for Maintenance, the original designation of the unit. The sea lions, suggested by the arms of Luzon, Philippine Islands, denote the area where the unit served during World War II. The three wavy blue bars refer to the three Presidential Unit Citations awarded the organization for Manila, Bataan, and Defense of the Philippines. The flaming sword, suggested by the arms of Bataan, represents that heroic action, and also reflects the unit's motto. The Philippine Presidential Unit Citation awarded the unit is symbolized by the stylized Philippine sun, and the annulet and saltirewise parallel rays simulate the sun on the New Mexico State Flag and refer to the unit's location.
The distinctive unit insignia was originally approved for the 515th Maintenance Battalion on 8 May 1970. It was redesignated for the 515th Support Battalion with description and symbolism revised on 16 May 1994. The insignia was redesignated retroactive to 1 September 2006, for the 615th Transportation Battalion with the symbolism updated.