1) L.F. & C. Model 1917 Trench Knife. The knuckle bow has six pyramidal protrusions and is marked at the top "U.S./L.F. & C./1917". OAL:14" with 9" triangular blade. 2) L.F. & C. Mark I Trench Knife. The right side of the handle is cast "U.S. 1918/L.F.&C-1918". OAL:11 3/4" with 7" blade.