This adapter makes it possible to mount most flat mount ACE type rear stocks and our Billet modular stock to your Cobray Semi Auto. It has a custom designed inner rear spring spacer that replaces the OEM part. This allows the bracket to be bolted to the gun and improve strength. The adapter is finished is jet black anodize and comes complete with threaded insert, allen wrench and instructions on installation. Call for questions. (gun & other parts sold separately) NFA rules apply, Addition of this item may require additional paperwork to be filed with the ATF, check with your local dealers. FLAT/MATTE black finish.