A remote filler neck with a 45-degree bend, used when the tank filler and the point you actually pour fuel into cannot be in the same place. That is the norm on boot-mounted fuel cells, where the cell sits low in the boot floor but the filler needs to come out through the rear quarter or boot lid. The 45-degree angle turns the hose run gently rather than kinking it, keeping fill rate high so the nozzle does not keep cutting out or blowing fuel back at you. Connect it to the cell with suitable filler hose and clamps. A worthwhile part of any tidy fuel cell installation where the filler position is dictated by the bodywork.