Description
On a red square, one point up, 2 1/2 inches (6.35 cm) in height and 2 1/2 inches (6.35 cm) in width a white stylized fortress, embattled on its outer edges and voided of the field, surmounted by a vertical white sword, point up and hilted yellow, all within a white 1/8 inch (.32 cm) border.

Symbolism
Scarlet and white are the colors used for the Engineers. The four corners of the crenelated square allude to their four campaigns in World War II, Normandy, Northern France, Rhineland and Central Europe. The four sides of the central red square stand for planning, training, construction and combat support. The sword symbolizes preparedness in peace and unrelenting fulfillment of Engineer missions in time of war. The white outer border symbolizes unit integrity.

Background
The shoulder sleeve insignia was approved on 10 February 1966. (TIOH Drawing Number A-1-409)