Patriot Ordnance Factory 00517 Buffer Tube .308 Anti-Tilt AR-15 7075 T6 Aluminum 8.2" X 1" X 1" The Mil-Spec 7075-T6 aircraft aluminum Anti-tilt Buffer Tube uses carrier cradle extensions to ensure that the carrier is always supported by the buffer tube, even when the bolt is forward. This prevents carrier-tilt and premature wear on the buffer tube. Thusly, the buffer-detent button doubles as a lock that stops the buffer tube from rotating and becoming loose under extreme operation conditions. Type: Buffer Tube Model: AR-15 Dimensions: 8.2" x 1" x 1" Size: 308 Material: 7075 T6 Aluminum Finish: Black