1mm. While AP promoted the watch as “Excess-Thin,” enthusiasts continued to make reference to it as “Jumbo” offered its 39mm case. Other slight adjustments incorporated a change from a white date wheel to some black Variation on the blue and black dials along with the addition of the double-deployant clasp https://www.watchesworld.com/a-guide-to-10-of-the-best-dress-watches/