*Adapter with Upgraded Folding Adapter and (ATF APPROVED) Shockwave Blade Stabilizer 2.0 for M-11/M12 Cobray Semi Auto. This rear stock adapter is a two piece design cut from the same aluminum as most AR receivers, machined to cradle the receiver for added strength. It has a custom designed inner rear spring spacer that replaces the OEM part. This allows the bracket to be bolted to the gun for improved strength. Upgraded folding adapter offers upgraded machined parts, machined improved locking buffer tube slot to prevent turning, upgraded hinge spring, improved locking hinge, slimmer design and harder coating. Kit also includes Shockwave Blade, Mil spec tube and Castle Nut. Allen wrench and instructions included. ATF letter can be printed from the KAK industries we site.