1mm. Although AP promoted the watch as “Extra-Thin,” fans continued to consult with it as “Jumbo” given its 39mm scenario. Other slight improvements included a switch from a white day wheel into a black Variation around the blue and black dials along with the addition of a double-deployant clasp on https://www.watchesworld.com/a-guide-to-10-of-the-best-dress-watches/