o-ring size for din to yoke converter?

[redacted]

I am talking about this
We use those on DIN tanks to make them YOKE compatible.
It has two o rings one on each side. A 213 seals the back of the insert with the tank a 111 or 112 seals the insert onto the Yoke. Different manufacturers use different thread size and o rings hence you have two possibilities
Those can give problems on some regulators brands which tend to leak no matter what, I had this happening to my MK25 in Egypt until I change the reg to DIN. My Mares MR12 never leaked with the same tanks!

A din insert has an outer diameter of about 7/8th inch. A 213 o-ring has an ID of 15/16th inch and an OD of 1 3/16th inch and 1/8th inch thick. I believe it is used on some older steel HP tanks.

 

[Interceptor121]

I think you are right now that I measure it. The two orings are different on the two sides. Thinking about it one could be a 111 (the one on the tank valve) and the other a 112 (on the regulator)
In fact if you put a 111 on both sides sooner or later it starts cracking and leaking