This combination of our rear stock adapter and tactical padded buffer tube is easy to install. The adapter is finished in jet black anodize and the buffer tube has a black oxide finish. Completely assembled, all you have to do is thread our bolt and lock washer into the threaded hole on the underside of your gun, lock it in place the supplied Allen wrench and its ready to go. Pistol tube length is 7.75". (gun & other parts sold separately) NFA rules apply, Addition of this item may require additional paperwork to be filed with the ATF, check with your local dealers. Fits 5.7x28mm with Threaded slot on underside of rear receiver.