A gold color metal and enamel device 1 1/8 inches (2.86 cm) in height overall consisting of a red demi-fleur-de-lis issuing from behind the upper vertical prong of a black caltrap on a gold background and all encircled by a continuous blue scroll, arched and divided in three folds at the top and bearing three white stars and in base the inscription "SERVICE BY SUPPORT" in gold letters.
The caltrap, a device used to impede the progress of enemy troops, together with the fleur-de-lis and he color blue commemorate the action I the vicinity of St. Barthelmy, France during World War II and the award of the Presidential Unit Citation. The three stars refer to the campaign credits earned during World War I. They also allude to the State flag of Tennessee and to the home area of the organization.
The distinctive unit insignia was approved on 15 February 1974. It was rescinded on 1 September 1976.