These unique fittings feature a -6 AN o ring boss port on one end, and a 5/16″ hose barb on the other end. By use of these custom fittings, plumbing an aftermarket fuel system is much easier without need for extra fittings and ugly adapters. We manufacture these fittings in house from 6061 aircraft aluminum using the most precise CNC machines. Each fitting is complete with a Viton o ring that will withstand corrosive fuels, such as ethanol.