Description
A square 2 inches (5.08 cm) in length on each side with one point up and a white border 1/8 inch (.32 cm) in width enclosing a scarlet field divided vertically by a white bar indented on both sides between two white right angles, their apexes coincident with the center indentations of the vertical bar, and their legs terminating at the border.

Symbolism
Scarlet and white are the colors used for the Corps of Engineers. The sawtoothed bar at center and the right angles are suggestive of the construction mission of the unit. The X-shape formed by the two right angles refers to the military symbol for a brigade. The unit's numerical designation is roughly indicated by the four sides of the square, with a Roman numeral XI formed by the two right angles and the vertical bar at center.

Background
The shoulder sleeve insignia was approved on 20 December 1973. (TIOH Dwg. No. A-1-569)