Braided fuel hose

AN stands for Army/Navy, which originally created the spec for their own use. Sizes are in 16ths of an inch, example is -8AN is 8/16" or 1/2" ID line. For today's fuel it is recommended to use a PTFE lined hose as the new fuel eats the rubber liner. There is a different spec for in tank hose that will be submerged in fuel.