1mm. When AP marketed the watch as “Extra-Thin,” lovers continued to make reference to it as “Jumbo” supplied its 39mm circumstance. Other slight variations involved a swap from a white date wheel to some black Variation to the blue and black dials and the addition of the double-deployant clasp on https://www.watchesworld.com/a-guide-to-10-of-the-best-dress-watches/