cappy208.
Yes I've fitted 2, one to my Perkins 4236 powered Birchwood.
The old Jabsco cover with little fiddly screws, (one always drops in the bilge) made checking/changing a pain.
The cover is machined brass.
Brilliant improvement, after I fitted one I never fitted an impeller even after cruising from Ireland to Spain. I checked the impeller and replaced it 'just in case', when I got there.
Use loads of washing up liquid to coat the interior walls of the pump housing and the impeller when fitting, it makes the job so easy and lubricates on first start up.
Use a plastic tie wrap to compress the blades for easy impeller insertion.
Don't worry if the blades of the impeller aren't lying the right way because the moment you start the motor they flip into the right direction.
Have plenty of paper towels to clean hands etc.
The knurled nuts on the Speedseal only need to be hand tight firm, the whole idea is to be able to undo them without tools to make impeller change quick and easy.
I was so please with the Speedseal that when I bought 'Snow Mouse' I immediately bought the later modified 'Run dry' version, even better.
I'm just a happy satisfied user.