A Silver color metal and enamel device 1 1/8 inches (2.86 cm) in height overall consisting of a shield blazoned: Argent a lion rampant Gules, on a chief embattled of seven Azure three fleurs-de-lis Or. Attached below and to the sides of the shield a Blue scroll turned Silver inscribed SEMPITERNAL SUPPORT in Silver letters.
Award of the Distinguished Unit Citation and French Croix de Guerre for action at Mortain is represented by the blue and white field with three gold fleurs-de-lis in chief, an adaptation of the arms of that city. The battlements signify the units campaign credits for both World Wars, and the red lion denotes the Belgian Fourragere received for service in Belgium and the Ardennes.
The distinctive unit insignia was originally approved for the 230th Supply and Transportation Battalion on 12 May 1967. It was redesignated for the 230th Support Battalion on 20 February 1974. The insignia was redesignated for the 105th Engineer Group on 6 October 1982.