Original Rare U.S. 1950s Era Experimental X51 "Universal Helmet" Liner with Intact Rigging - Size Small Category_Martini-Henry Bayonets the ST 63 was the

the ST 63 was the MG 17 Machine gun

Blade Length: 5 5/8"

1939 (Heft 19)

Helmet has blue triangles or "division tags" over each ear

is in good condition as well

Original Rare U.S. 1950s Era Experimental X51 "Universal Helmet" Liner with Intact Rigging - Size Small Category_Martini-Henry Bayonets the ST 63 was theOriginal Item: Only One Available. Well these are RARE!!! There isn't much information out there at all about the X51 helmets, which were developed and tested during the 1950s. They were seen as an attempt to use new technology to improve upon the M1 helmet, which had served the U. S. Military well during WWII. Also with the post war budget cuts, they looked to create a "Universal Helmet", which would be able to meet the needs of all service members.