Compensator for the Winchester Model 1907  07 .351 SLR rifle as originally installed by Hyman Lebman for the rifles he built for John Dillinger.  These require threading the barrel of your rifle 5/8-24. Supplied with a Marbles 41W 3/32 brass bead front sight (204131). Once threaded these compensators have an 8-32 set screw on the bottom side to fix them to the barrel. Installation will require removal of your barrel to do a proper job of threading. Finish is polished blue.