Hello.
I'm searching for my AA12 gbb project the exact thread dimensions of exhaust valves.
They look all the same, so it's possible that they have all the same dimensions.
https://www.redwolfairsoft.com/prowin-release-valve-for-prowin-model-17-18-hi-capa-mws-m4a1-gbb-gas-magazine.html
Edit: looks like nobody is willing to help.