THERE ARE MANY VERSIONS OF THESES WATCHES. The Bezel is 39.10mm outside. 30.50mm inside around glass.34.40mm backside where is attached to the case. The item "Chronosport Chronograph Military Pilot 39.10mm Slide Rule Flat Bezel Lunette NOS" is in sale since Tuesday, June 15, 2021. This item is in the category "Jewellery & Watches\Watches, Parts & Accessories\Watches\Other Watches". The seller is "highendwatchparts" and is located in Vancouver, BC. This item can be shipped to Canada, all countries in Europe, United States, Japan, Australia.