The Proto MaXXed RailTM features Fuse Bolt Technology, color coded O-rings for simplified maintenance, and a host of other features. These features, like a 2-piece Micro Honed 14" barrel, lever lock adjustable feed neck, Ultralite on/off airport, quick release macroline hose, and custom MaXXed Rail marker case combine to make the MaXXed Rail the gun of choice. The MaXXed RailTM was designed for top-level performance at a reasonable price. You get $180 of upgrades for only $79 Dollars!!