This is the right component if want to mount an M4 type buffer style stock to your M-11 SMG. This steel adapter slides into your existing wire stock slots and is secured by a button head bolt and a threaded internal block. Bolt, billet block and Allen head bolt (provided). The Rear of the adapter is flat with an AR Buffer Tube Threaded for an AR M4 stock.(gun, rear stock and other accessories sold separately) Installation instructions. Please call with questions, Weighs about 6 ounces.