This is a very rare in the box m5a1 bayonet for the M1 grand rifle. Made it by the JND tool company the box is marked m5 on one side and M5e1.
According to Gary Cunningham's book the E was for experimental. Please see pictures for actual condition of bayonet. The item "J&d Tool M5a1 Bayonet In Box Experimental Korean War Garand" is in sale since Sunday, August 13, 2017.
This item is in the category "Collectibles\Militaria\WW II (1939-45)\Original Period Items\United States\Edged Weapons". The seller is "damcon3" and is located in East Windsor, Connecticut. This item can be shipped to United States.