Hi all,
If you've read my other posts you will know I'm new to watch repaires.
I've just aquired an Omega Seamaster 166.003 case and seperated it into its component parts to give it an ultrasonic clean.
Three parts went into the bath and four came out, the fourth being a flexible metalised ring, it looks like a metalised plastic of some sort. It isn't the case back gasket because I'd already removed it. The only place it fits is the movement clamp groove.
What is it for?
Photo attached
I'm restoring another Seamaster which has the same casing and a 562 cal movement, and there was not a similar ring in that one.