The RQD 9mm Tri-Lug HUB is fully compatible with 1.375x24TPI ,HUB, compatible suppressors available today and is made from titanium and stainless steel components. This HUB works with all B&T/HK Spec Tri-Lug 9mm barrels. It is simply threaded into compatible suppressors and tightened with a spanner wrench. HUB assemblies can be semi-permanently attached using Rocksett or other thread locking compounds if the end user chooses.