A Gold color metal and enamel device 1 5/32 inches (2.94 cm) in height consisting of the coat of arms blazoned: SHIELD: Sable, a fess checky Argent and Azure between three high explosive shells each debruised by a leopard's face Or. CREST: That for the separate battalions of the Pennsylvania Army National Guard: On a wreath of the colors Or and Sable, a lion rampant guardant Proper, holding in dexter paw a naked scimitar Argent hilted Or and in sinister an escutcheon Argent on a fess Sable three plates. Attached below the shield a White triparted scroll inscribed "PUEBLA TO THE MARNE" in Gold letters.
The shield, based on that of William Pitt, is adapted from the coat of arms of the city of Pittsburgh, the home of the unit since 1831. The three gold H.E. shells, charged with a leopard's face, are taken from the arms of Duquesne, indicating the origin of the organization's nickname, the Duquesne Grays. "Puebla to the Marne" represents the long fighting record of the unit, which was mustered into Federal Service in 1846 as Infantry.
The distinctive unit insignia was originally approved for the 176th Field Artillery Regiment on 11 August 1924. It was redesignated for the 176th Field Artillery Battalion on 15 September 1942. It was redesignated for the 689th Antiaircraft Artillery Battalion on 19 November 1953. The insignia was redesignated for the 176th Artillery Regiment on 26 September 1961. It was amended to correct the wording in the motto on 22 November 1961. It was redesignated for the 176th Air Defense Artillery Regiment on 11 July 1972. The insignia was redesignated for the 128th Support Battalion with the description and symbolism revised on 8 December 1992.