This stock adapter allows you to attach your favorite AR 15 stock to your MPX rifle or registered Short Barreled Rifle. This stock adapter consists of our MPX Stock Adapter with an AR 15 buffer tube adapter. Compatible with Mil-Spec or Commercial buffer tubes. Can also be used to attach a KAK Shockwave Tube and Shockwave Blade Pistol Stabilizer or other pistol stabilizing arm brace to a Scorpion pistol. Can be converted into a folding stock by adding one of our folding stock mechanisms.