1mm. Even though AP promoted the watch as “Extra-Thin,” admirers continued to confer with it as “Jumbo” supplied its 39mm situation. Other slight variations incorporated a change from a white date wheel to some black Model about the blue and black dials as well as addition of a double-deployant clasp https://www.watchesworld.com/a-guide-to-10-of-the-best-dress-watches/