Improved fixed barrel spacer is compatible with our EVO-9 Ti-RANT 9/9M and Illusion 9 silencers. a Wave spring to tension the rear cap while assembled to prevent unintended loosening during use. a Employs an o-ring on the inner diameter to ensure proper alignment of the spacer relative to the piston body. a Ensures full thread engagement between the silencer body and the rear cap. When installed properly NO gap between the silencer body and the rear cap. Different from the prior design which purposely left a gap for visual identification.