It's just about 35mm, wears rather large cause it's all-dial. Very similar to my steel one with bombé lugs.
I find it the perfect size for my wrist, esp. with the straight (but comfortably curved downward) lugs. I like the fit better than the other with the ribbon lugs (that case was 1-2mm bigger, too).
OK, here is a (not too good) wrist shot (need to get this baby outside on a sunny day, maybe next year!):