I use the on a Gretsch 6120T Players Edition because it was impossible to get the pickups up to TV-Jones recommended settings.
Finally I got the classic compressed Gretsch-sound, i.e. no more thin sound.
Pros: If you?ve got a guitar that you can?t adjust the pickups up to about 4 mm. from the (open / loose) strings these are the ticket.
Easy to install on most guitars I guess.
Cons: I had to make the hole a bit wider to fit the original Gretsch pickups - TvJones should consider making the rings easy to customize for those who don?t have a full arsenal of tools. I used the Dremel on mine.
There are 3 rings included in the bag, I think I could have used one more on the bridge pickup. Depending on how the guitar is set up the bridge pickup is just within the recommended distance from the strings or 2 mm. to far away which means a lot with some pickups.