And does it work when not in VL form?

It works out of Vampire Lord form. Not sure on how much exactly it increases the regeneration rate but it is substantial.

Its one of the main reasons why siding with the Volkihar benefits your character more than siding with the Dawnguard.

According to the usep it adds 2 magicka per second.

I love the new jewelry you get on the vamp side...

It adds 100 magicka and 100% magicka regeneration in both forms, I verified this in the creation kit.

Oh, ok, thanks. Have heard people saying that the regeneration doesn't work in non vl form. thanks for clarifying.

Guess im doing Volikhar side for this character, haha.

Ring of Erudite is pretty awesome. I started out as a pure assassin but having this ring has made me cross over into the conjuration school of necromancy and I don't regret it at all! Definitely fits this character RP wise too.