This is an original WWII German M1931 helmet liner system. The leather liner is a size 57; to be paired with a size 64 helmet shell. It features a zinc band and manufacturer's date of 1943. It exhibits the unique spliced leather factory variation. The leather is still soft and supple and the liner comes with its original drawstring still intact. This would be an ideal liner system for an M40 or M42 helmet.
WWII German M40, M42 64/57 Helmet Liner