"The MOE SL Stock – Mil-Spec Model (MOE Slim Line) is a drop-in replacement buttstock for AR15/M4 carbines using mil-spec sized receiver extension tubes. Designed for the modern battlefield, the sleek profile, dual-side release latches, rolled toe, and angled rubber butt-pad are optimized for use with body armor or modular gear and provides for efficient shoulder transitions. Made in U.S.A. FEATURES Mounts on mil-spec sized carbine receiver extension tube (not included) from manufacturers such as Colt, LMT, Ruger, S&W, SIG, and others (please see the note below) Sloping cheek weld combines a slim profile with user comfort Dual-side release latch provides easy adjustment while remaining anti-snag Premium chrome-silicon lock spring provides positive locking and long service life Internal anti-rattle feature minimizes wobble on receiver extension tube Rubber butt-pad offers an anti-slip surface and increases impact protection Rollover on the toe allows for easier shoulder transitions and better fit when using body armor Compatible with Magpul ASAP®, ASAP® QD, and other receiver-mount sling attachments Sling Mounts Rear – Integral push-button QD swivel sling mount accommodates up to 1.5" swivels (ambidextrous) Rear/Bottom - 1.25" sling loop NOTE: There are two basic sizes of M4 Carbine receiver extensions (buffer tubes): mil-spec and commercial-spec. If you have a commercial-spec size extension on your rifle, make sure to order the Commercial-Spec MOE SL."