This is the AEF's answer to the heavy German wool uniforms. It's a M1918 Trench Knife... they had a triangular blade only meant for stabbing. They are really hard to find in this shape... being over 91 years old. This one was made for the Gov't by LF&C (Landers, Frary & Clark). These were issued in great numbers. The knife most people think of when you say Trench Knife was the later M1918 Mark 1 which was too late to get into WW1 but was available to "Special Troops" in WW2. These were the only actual trench or knuckle knives the US ever had as officially issued items. There were however dozens of custom knives carried...