When purchasing CMMG or any other brand from eGoods365.com store, you can be sure that (a) you are purchasing from US based company with the most responsive and friendly customer service; (b) an authentic, not a counterfeit and not a refurbished product.

CMMG's Fastback Receiver Extension is a unique product that allows you to quickly and easily adjust the position of your stock or stabilizing brace. This system is designed to accept all mil-spec buffer tubes and gives you multiple length options. To adjust the length, simply insert the indexing screw into the desired hole, and you're ready to go. The Fastback Receiver Extension is made from durable aluminum and comes with a hardcoat-anodized finish. With six different position settings available, you'll be able to find the perfect fit for your needs. Additionally, the extension comes with the necessary P3 adjustment screw. Once you've adjusted the length, simply pull the stock or brace to the rear and it will slide back until it hits the screw, leaving you locked into place and ready to shoot!