Can anyone tell me what size, or more specifically what thickness gasket I should order to replace the case back gasket in the 43mm (ref. 241682.1) Victorinox INOX?

I prefer to do my own battery changes and since they're cheap enough, I generally replace the gasket whenever I do a battery change but I just can't find any documentation on the correct size of gasket for the case back.

Thanks in advance for any help you guys can offer!