Also known as a unit crest or DUI, the Distinctive Unit Insignia is worn by all Soldiers (except General Officers) in units that have been authorized to be issued the device. It is worn centered on the shoulder loops of the Army Green Service Uniform (AGSU) and the blue Army Service Uniform (Enlisted only) with the base of the insignia toward the outside shoulder seam.
Full guidance on wear of the DUI is found in DA Pamphlet 670-1,
Section 21-22, "Distinctive unit insignia."
♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦
Special Troops Battalion, 1st Brigade Combat Team, 1st Cavalry Division—also called the 1st Brigade Special Troops Battalion and nicknamed "Centurion"—was formed from the Headquarters Company of the Division’s 1st Brigade on 17 October 2005 as part of the Army’s move toward a brigade-centric force.
Deployed to Iraq a little over a year later, the Battalion’s first tour in support of Operation Iraqi Freedom lasted some fourteen months. It would be awarded a Meritorious Unit Commendation in recognition of its outstanding performance during that time nearly six years later on 12 November 2013. It would be one of four Meritorious Unit Commendations the Battalions, known as “Centurions,” would earn before inactivation in 2013, putting true meaning to the unit motto “VIRES PER FEROCITE,” Latin for “Strength Through Courage,” found on the battalion’s Distinctive Unit Insignia (unit crest).
In addition to a Headquarters and Headquarters Company, the Special Troops Battalion of the 1st BCT, 1st CAV had a Military Police platoon, a CBRN platoon, a Military Intelligence company, and a Signal company
As part of the Army 2020 Force Structure Realignment plan, the 1st Brigade Special Troops Battalion (STB) was transformed into the 91st Brigade Engineer Battalion (BEB) when it was reflagged in October 2013. Before the change, the STB had a single company of Engineers; as the 91st BEB, it consisted primarily of Engineers within a half-year of the reflagging ceremony.