Case across from lug tip to lug tip is 29mm. This watch is 50 years old yet it was never used. Note that this is a true collectors item. If you want to put it to use it must be lubricated first.
The movement currently has 50 years old lubricant in it which is probably dry by now. If requested I can have the watch freshly lubricated and primed for you but I also understand that some collectors would prefer to leave this watch unopened. Collecting NOS is really a hobby in itself. The item "Vintage Certina Myfair Ladies Automatic Diver Sector Dial 1960s NOS New Old" is in sale since Friday, September 13, 2019. This item is in the category "Jewelry & Watches\Watches, Parts & Accessories\Wristwatches". The seller is "hotrodpropaganda" and is located in Budapest,Pest. This item can be shipped worldwide.