Who else would you trust for aftermarket upgrade parts than Billy Wing. Billy is a 12 year Pro veteran, and one of the head designers of DYE’s extensive gun line. The B-Wing bolt kit is hand polished and fitted to ensure pro level performance. The mirror like finish allows for a lower pressure, which renders less kick. The B-Wing bolt also helps prevent bolt stick, which improves shot to shot consistency. Compatible with 2007 to 2010 Rail markers..