Brownells offers this kit that contains both the Magpul CTR buttstock and all mounting hardwear needed for an easy installation. Includes CTR buttstock, Mil-Spec buffer tube, carbine buffer, chrome silicon recoil spring, receiver end plate and castle nut. Features a friction locking mechanism that eliminates movement between the buffer tube and buttstock for a solid “feel” when mounting rifle to shoulder. Heavy duty, spring-loaded hand lever allows fast length-of-pull adjustments. Nylon polymer body provides maximum impact and heat resistance, with molded-in reinforcements at stress points. Accepts a variety of ambidextrous sling attachment options, including web slings and single-point, push-button sling mounts. Comb contour is wider than standard issue M4 stock to help shooter maintain a solid cheekweld. Synthetic rubber buttpad increases comfort and helps prevent slippage. Fits buffer tubes that accept both four- and six-position collapsible stocks. Available in Black, Dark Earth, Gray and O.D. Green, so you can match the color of your stock to your tactical rifle's color scheme. Mil-Spec fits smaller 1.14" O.D. buffer tubes on Colt-manufactured M4 and similar mil-spec carbines.