Our 6 Position Anti Tilt Buffer Tube Kit uses “carrier cradle” extensions to ensure that the carrier is always supported by the buffer tube. This prevents carrier-tilt and premature wear on the buffer tube. As a result, the buffer-detent doubles as a lock that stops the buffer tube from rotating and becoming loose. POF-USA’s design also features three extra drain holes for marine environments. The kit also comes with a Mil standard carbine buffer and carbine buffer spring.