This is probably a really dumb question :wtf: But those Fernandez Sustainers, what exactly are they? What are they and not what do they do? I mean, I know they sustain notes for as long as you want, but what exactly IS it? Is it some kind of device that goes on the bridge? Is it a cover for the bridge humbucker? Is it a humbucker by itself, and you have to remove the old one?