FJ helmet size

[boneshaker]

Can anyone tell me about FJ helmet sizes? I am wanting to get a FJ helmet for reenacting, but I have herad that the FJ's sizes differ from M35, M40 & m42 helmets. Is a 57 cmm liner the same in a FJ as in a M35 or do you need a larger size?
Thanks

[KradSpam]

The liner is the only size you need to worry about, forget the size of the shell.

57cm is 57cm........

[boneshaker]

Do you know what size liners go with what size shells?
Thanks

[davejb]

Fallschirmjager helmet liners came in nine sizes and were used in three shell sizes:

liner sizes 53 54 55 were used in size 66 shell
liner sizes 56 57 58 were used in shell size 68
liner sizes 59 60 61 were used in shell size 71