Colonial WWII U.S. Navy Mark I - COL10000 Colonial Knife Company. WWII U.S. Navy Mark I Combat Utility Knife. 10 1/4 overall. 5 1/8" high carbon steel blade with black anti-reflective finish and USN tang stamp. Grooved black metal handle with integrated guard and pommel. Tan leather belt sheath embossed U.S.N."