40mm (and very wearable) and is 100 meters water resistance. This Omega does seem a tad thick, especially with a manual movement. I did a search and read quite a few early reviews, and nobody mentions the thickness of the watch, so Omega is being coy with this. At $8,650 for steel, the price seems reasonable. But I'd prefer a smaller watch...the Daytona is a perfect size imho.