Can you name the part that is?

.....the kahler type locking nut that was after the nut?....y'all know what I'm talking about it was four screws and fit after the nut........it's was a Kahler thing....they're the only ones that did that.....what I'm asking is....is this named something other than a locking nut? because it wasnt a "nut" .....just trying to find the part for a TP6 tailpiece Les Paul.......Thanks for the help.....