A fuel cell fitting in AN6, used to bring a line into or out of a fuel cell, surge tank or custom reservoir. Fittings of this type mount to the tank and present a standard AN6 male flare on the outside, so you can plumb the tank with ordinary braided hose and AN hose ends rather than improvising with barbs and clamps, which is what scrutineers and insurers prefer to see. AN6 is the right size for return lines, vent lines and feeds on moderate-power engines. Make sure the sealing arrangement and bolt pattern match your tank’s existing flange before ordering, and use fuel-compatible sealing hardware on assembly.