Aero Precision Enhanced Carbine Buffer Tube, Fits AR10/AR15, Anodized Finish, Olive Drab Green APRH101803C Buffer tubes serve a vital function in the AR15 recoil management system" but why can't they be more? They took a whole new approach when designing their Enhanced Carbine Buffer Tube by including features like carrier support extensions" position guide drain holes and ramping the design of the tube. These features add reliability" security" and simplicity that traditional mil-spec buffer tube options historically overlook.