1mm. Whilst AP marketed the watch as “Additional-Thin,” admirers continued to consult with it as “Jumbo” given its 39mm scenario. Other slight adjustments involved a change from a white date wheel to some black Variation on the blue and black dials as well as the addition of a double-deployant clasp https://www.watchesworld.com/a-guide-to-10-of-the-best-dress-watches/