Rolex GMTII Crystal Size / Source

[amedman3]

I bought a Rolex GMT II case from another m2m. During assembly I cracked the crystal. I measured the crystal and it appears to be 30.0mm diameter which seems like an odd size from what I found on the forum. Can anyone help me with a replacement, Clark, or other listing for this?

[ceocorona]

Without having more insight into the origins of the case this will be a trial and error. Clark crystal isn't too expensive. I'd definitely start there. If the crystal opening requires a unique size you may be in a predicament...