This is our newest rear stock design. It offers a solid stock design and with the folding adapter weighs just over 1.3 lb. with the folding adapter. It measures about 9.25" from the rear of the receiver. Finished in jet black anodize. Replaces the factory push button OEM parts with an adapter and a threaded, machined inside block. Folding adapter can be switched to fold to the left or to the right. Instructions and Allen wrench included. Fits Mac-10 SMG & M-10 Open Bolt Semi Auto only. (gun & other parts sold separately) *NEW FLAT/MATTE BLACK FINISH.