The NX original nitrous rails feature a billet aluminum body anodized in both blue and red. This package includes 2 single hole rails in blue, two single hole rails in red, fittings, and pipe plugs. The rails themselves also include 4 1/8 in. input fittings as well as 16 5/16 x 24 fittings. These rails would be spectacular for those looking for a clean look while also using less space than the traditional distribution bocks. NOTE: The rails will require tapping for all fittings!First in Quality, first in technology, Nitrous Express, the Next Generation nitrous company!