I'm about to make a similar stuff for my arca Fline 69...

i'm interested in the tha that it is double folded !
i just need the size of the inside window, i mean the hole between the two bellows.


"Wide angle "Bag" bellows for Linhof M679 and M679CC 6x9cm view cameras. Double folded, for extreme extension.
For use with lenses of 28-90mm focal length."