This streamlined, lite modular stock includes a thin folding adapter and a flat mount Adapter for the Master Piece Arms .45 acp. Offers a sleek, slim design with a padded buffer tube for cheek weld comfort and a molded rubber butt pad for additional recoil absorption. Stock can be folded to the left or right, we build it to fold on the left. End to end, stock and adapter measures about 9.5". Fits all Master Piece Arms .45ACP guns and rifles with a factory threaded hole. Easy installation. * NFA rules apply, Addition of this item may require additional paperwork to be filed with the ATF, check with your local dealers. Installation instructions included. (gun and other accessories sold separately)**TELL US IN THE COMMENTS SECTION OF YOUR ORDER IF YOU HAVE AN OPEN BOLT MAC-10, WE NEED TO GIVE YOU A DIFFERENT BOLT AND INNER THREADED BLOCK.