This is an original pre-WWII German M1931 helmet liner system. The leather liner is a size 57; to be paired with a size 64 helmet shell. Its reinforced aluminum band showcases a 1938 production stamp by Metall-Lederverarbeitung W.Z. Bln. Ch'burg 5. The leather is unfortunately deteriorated. The leather's underside is stamped with an inspector's mark of 'F.F.' This would be an ideal liner system for an M35 helmet in equally rough condition. Split pins sold separately.