The Ops-Core Picatinny Adapter is designed to interface with the ACH-ARC Rail Kit for the MICH/ACH and FAST Helmets.  It’s proprietary dovetail rear design allows it slide right into the ARC Rail system, providing the user a four-slot piece of 1913 rail for mounting a variety of accessories.  The adapter features a quick release design, but can be semi-permanently installed with a tension screw.