Fits griffin armament optimus - SilencerCo Delta Adapter

Fits a little looser than sick flash hider but as soon as it hits the retention tab everything tightens up. I don't think this will be an issue though. The actual product looks different from the pic optics plant has. There is a taper for the retention tab to ride on allowing the mount to be screwed on all the way down. Also wanted to mention that this fits Griffin Armaments Optimus and Revolution series. I've been looking for a solution for this 18x1 problem for a while. There are thread adapters for around $80, and then I wouldve needed to buy a fixed mount from Griffin for an additional $85. There was also the option of rethreading my barrel which would have ended up costing the same or more. This is a great solution for cheap(er).