Sorry Joe What I can tell you is that these 63 cm white rubber gaskets does not fit my lid that I bought last year. and it calls for a 63 cm too small for my lid. I like these white rubber gaskets. A good product but what good if it doesn't fit. It is possible that someone marked it wrong. Joe I just measured the inside of this 63 cm gasket without air and it measures 67 inches I hope this helps.

It can be used on any VCT if the size is correct

I found Marchiso heavy duty black rubber replacement gaskets on Google. I have purchased a couple of replacement gaskets for my variable lid fermenters and also found it very hard to get the right size. Even when you find the right size these things are very difficult to get on the lid. Stay away from the clear plastic ones if you can - they don’t even last a single season.

We have used these on the Marchisio 300L Variable Tanks that have an inner diameter of 65cm for a few years without problems.

Yes Wet lid where gasket slides over and area where it sits when installing.