Finally an easy and effective way to attach your Ti-RANT 45 to a 300AAC BLK host! Allows all Ti-RANT 45 and Ti-RANT 9M HD variants to be directly threaded to a 5/8-24 barrel for use with subsonic 300 AAC Blackout ammunition. Can also be used with some western rounds (357 mag 38 spl 44 mag 45LC and 44 spl). Replaces the Ti-RANT piston and driving spring to render it appropriate for use on a fixed barrel. Innovative wave spring design is used to tension the rear cap while assembled to prevent unintended loosening during use. When installed properly there will be NO gap between the silencer body and the rear cap. Conventional stand-alone fixed barrel spacer is not needed as this part effectively combines the 5/8-24 piston and fixed barrel spacer into one part.