Magpul BDA Mil-Spec/Pistol Arm Brace - Black - TheMagpulBDA is an AR arm brace designed to improve the single-handed employment of large-format pistols. Through Magpulengineering and design, the BDA offers an optimized stabilizing accessory with reliableMagpulquality. By simply swapping out the interchangeable clamps, 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 brace's 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 andMagpulinnovation, the BDA Arm Brace is a simple solution to improving your AR pistol. Made in the USA Platform: AR15, M4 Compatability: Fits Mil-spec carbine or A5 receiver extension equipped AR pistols and cylindrical Pistol receiver extensions with an outside diameter of 1.175in - 1.25in Non-adjustable/fixed position only for use on AR pistols Interchangeable clamps for compatibility with both Mil-Spec carbine, A5, and Pistol receiver extensions Ambidextrous rear QD cup allows sling tension to be applied while firing with one hand to improve stability