What materials do knights armament use on their suppressors? Their is not a lot of information online about them.

KAC has been a supplier for spec op troops for many years now. I would be confident that they meet any spec said. This is not NASA where the lowest bid wins the equipment is top drawer.
These are a few of the products:https://images.app.goo.gl/wyxJFDCkmeV5cKeQA
-CL