Something for others too. When you get the aluminum flanges and gasket as a kit they match. But the jagmte gaskets by themselves are like 1m bigger ID and OD for the original plastic flanges so if you order a replacement o ring make sure to specify its for a plastic or aluminum or stainless steel flange.
JAGMTE mentioned this on a random YouTube video but I did not see it on their site etc. Not a big deal but ya the gasket I bought septfits loose and the ones that came with the flange are nice and snug etc