Description
On an Army green 2 1/4 inch (5.72 cm) square background, the monogram "O.T." in red, the "O" 2 inches (5.08 cm) in length and 1 1/4 inches (3.18 cm) in width, long axis horizontal, and the "T" 2 inches (5.08 cm) in width and 2 inches (5.08 cm) in length; all elements of the letters 5/16 inch (.79 cm) in width.

Symbolism
The letters "T" and "O" represent the states of Texas and Oklahoma, from which the personnel of the 90th Division were originally drawn.

Background
The shoulder sleeve insignia was originally approved for the 90th Division by telegram on 25 October 1918. It was officially announced by the War Department on 8 July 1922. It was amended to correct the wording of the description on 11 October 1922. The insignia was authorized for the 90th U.S. Army Reserve Command on 22 April 1968. It was reassigned and authorized effective 16 April 1996, for the U.S. Army 90th Regional Support Command. The insignia was redesignated effective 16 July 2003, for the U.S. Army 90th Regional Readiness Command. It was redesignated effective 17 September 2008, for the 90th Sustainment Brigade. It was amended to correct the effective date of the redesignation of the insignia for the 90th Sustainment Brigade to 16 September 2008. (TIOH Dwg. No. A-1-137)