The POF-USA 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. Furthermore, the buffer-detent button doubles as a lock that stops the buffer tube from rotating and becoming loose under extreme operation conditions. The anti-tilt buffer tubes also feature three (3) extra drain holes for marine environments. FeaturesMIL-A-8625F Type III Class 2 Flat Black Hard Anodize Finish7075-T6 Aluminum Construction3 Drain HolesAnti-tilt Carrier CradleMil-Spec size 1.148 diameter receiver extension (buffer tube) Notes:Replacement Compatible with All P415 and P416 rifles with 6 position buffer tube.Replacement Compatible with P308 rifles manufactured BEFORE October 2012 that used a 6-position Anti Tilt Buffer Tube! New P308 rifles feature a 7-Position Buffer Tube that utilize the standard AR15 Carbine Buffer and .308 A2 ...