The BDA is compatible with both Mil-Spec carbine and A5 receiver extensions as well as Pistol receiver extensions. An integrated rear QD cup provides ambidextrous sling mounting options, and the braces large lateral surface area supplies plenty of forearm contact. Combined, these features allow application of sling tension, drastically increasing single-handed control of the firearm. With a straight-forward design and Magpul innovation, the BDA Arm Brace is a simple solution to improving your AR pistol.