This AR Receiver Extension Kit is constructed from aircraft grade aluminum with rolled threading. The buffer tube has been hard coat anodized for maximum corrosion and wear resistance. A standard buffer spring and 3oz carbine buffer are included as well as a castle nut and lower receiver end plate.
This assembly kit will fit on all Mil-Spec AR 15 lower receivers. It is also compatible with most AR 308/AR 10 rifles but requires a modified buffer and spring for proper operation.