These are the most exact, high quality reproduction M31 German helmet liners available today. These are custom made in Europe and manufactured just like the originals including the maker "B&C Litzmannstadt" size and date stamp. They are completely assembled and ready to install in your helmet. These are NOT the Chinese or Indian copies out there, these Czech made liners feature galvanized steel bands with real pig-skin leather liners, just like the originals. They are indistinguishable from originals. Available in Size 68/61. 68 is the shell size. 61 is the head size (7-5/8). These liners fit larger German Helmets with a size 68 shell. Just look for the number 68 on the inside of the helmet brim.