This graphic schows the Shoulder Sleeve Insignia of the 1st Armored Corps.
US Army
[[:File:001-Armored-Corps-SSI.png|<a href="//commons.wikimedia.org/wiki/File:001-Armored-Corps-SSI.png" title="File:001-Armored-Corps-SSI.png">File:001-Armored-Corps-SSI.png</a>]] - original source: United States Army Institute of Heraldry