*On a disc 2⅝ inches (6.67cm) in diameter a white-edged blue triskelion with lower leg vertical between three white five-pointed stars on a green background all inclosed by a ⅛ inch (0.32cm) white border.
Symbolism
The green background with three stars refers to the hickory tree crest of the Tennessee ARNG.
The wavy blue three-armed partition represents the coming together of the Holston and the French Broad Rivers to form the beginning of the Tennessee River in Knoxville, where the regiment's headquarters is located.Background
The shoulder sleeve insignia was originally approved for the 278th Infantry Brigade on 19 March 1974.
It was redesignated for the 278th Armored Cavalry Regiment on 19 August 1977.
- US Army Institute of Heraldry
This  vector image was created with Adobe Illustrator.