What is the correct master cylinder for manual disc

The plated cap, which came with it, is a nice touch too.

One thing I did do was use a small amount of 3M Weatherstrip Adheasive to tack the rubber gasket to the lid. I cleaned both surfaces with Wax and Grease Remover first. I did this because the rubber gasket looked slightly deformed and I thought it might not seal against the body of the master cylinder correctly. Should not have had to do that but I didn't feel like hassling with sending it back. It is nice and dry after the drive and I believe it will stay that way.

The other thing to note is the master cylinder body surface that seals against the gasket is very nicely machined. Nice and smooth for a good seal.