A hex hose finisher for AN16 hose with a 30.58 mm internal diameter. At AN16 you are plumbing serious volume, typically intercooler transitions, large breathers or high-flow coolant lines, and the hose end needs a clamp that grips all the way round rather than at a single band. The finisher provides that while presenting a hex body that visually matches the machined AN fittings used elsewhere in the build. It is a straightforward way to bring an entire plumbing installation to a consistent standard of finish. Measure the outside diameter of your hose over the braid to select the right size, and seat the spigot fully before clamping down.