Who else would you trust for aftermarket upgrade parts for your DM than Billy Wing. Billy is a 12 year Pro veteran, and one of the head designers of DYEÍs 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 LPR pressure, which renders less kick. The B-Wing bolt also helps prevent bolt stick, which improves shot to shot consistency. Compatible with DM7 and DM8. For DM7Ís you must use the DM7 Bolt Can, not the Bolt Can included in B-Wing Bolt Kit.