The factory Remington is a 2 piece design, the threaded collar that screws on to the tube is a separate part from the extension. 1 piece ones are usually aftermarket, mine is from TacOrd, a solid hunk of bar stock metal. It works well with the detent barrel rings. Would probably need a clamp if it was on an Express.
No, I read about +2 extensions that are one piece and +2 extensions that are 2 pieces.
Well, I just learned something new. All of mine (+1 and +2) have been one piece.




























