exactly it is 31,71 mm

measured with a digital laser tool

ape aka www.heuerautavia.com

: Size is correct but these crystals use also teflon tension ring to
: fix the crystal into the case. The outer size, thus the opening
: in the case is 320. I have teflon rings wich I have to use with
: crystal size of 319...so the crystal of these 11630 Autavia's is
: obviously never 320 but always something less (depending on the
: thickness of the teflon tension ring ofcourse).

: Cheers,
: Abel.