The protection for the elbow. Unusually large example of 6” inside dimension. Made of a single piece with flared edge and riveted joint. Ridged at the middle to accommodate movement of the elbow in it padded sleeve. The surface tool finished and would have been coated with Brunswick black, a bituminous material, the black surface of black and white armor. That the surface is the original as made and finished is verified by the presence of a suspension leather inside. It was made, blackened and once part of an armor. Elegant form. Ex: Higgins Armor Museum with inventory number inside.