The Hellfighter Mod Kit it the perfect, ultra-fast California Compliant magazine lock solution for your AR-10 or AR-15. Juggernaut's modified quick-release take down pin, acts as a button to separate the upper from the lower just enough to disengage semi-automatic operation and automatically disable the magazine lock. Once your upper is separated and disengaged from semi-automatic operation, your magazine release is now operable. A simple tap closes the upper and re-engages the spring loaded take down pin and will quickly get you back in the fight. It allows you to keep all of your current features, including a pistol grip, a forward grip, and adjustable butt stock. You can even reinstall a mil-spec magazine release. This model has a black finish and is compatible with your AR-15.