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.The buffer-detent button doubles as a lock that stops the buffer tube from rotating and becoming loose under extreme operation conditions.Rails: BlackType: Buffer TubeFirearm Type: Buffer TubeFirearm Model: 8.20" x 4" x 4"Material: Mil-SpecFinish: Aluminum