NCO Marine Sergeant Coin Non-commissioned officers are known as the "Backbone of the Marine Corps." This 1.75" antique brass challenge coin features the rank of Marine Sergeant, topped with the curved text, "U.S. Marine Non-Commissioned Officer." Designed to resemble Marine Dress Blues, the front side is encircled with a scarlet stripe between two dark blue rings. This side is also covered with a protective clear epoxy coating. The reverse side showcases a 3D Eagle, Globe, and Anchor, surrounded by the words, "United States Marine Corps" and "Semper Fidelis."