The Magpul BTR AR Arm Brace enhances single-handed control and stability for your AR-15, transforming your shooting experience. Expertly designed, the BTR is compatible with Mil-Spec carbine receiver extensions and features a user-friendly adjustment mechanism for seamless operation. Its robust construction ensures reliable performance while maintaining classic Magpul aesthetics. Fits AR-15 Milspec Carbine Receiver Extensions Designed and Intended for Use in One-Handed Firing Rear QD sling mount for ambidextrous attachment and aids in stabilizing M-LOK slot provides additional sling mount location Elevate your AR pistol's functionality with the Magpul BTR Arm Brace.