A straight female flare swivel adapter in AN8, sized for the fuel feed, oil cooler and transmission cooler lines that make up the bulk of a performance plumbing job. AN8 hose is noticeably stiffer than AN6, so the swivel becomes more valuable rather than less: you can seat the 37-degree flare correctly and then turn the line to its natural resting position without loading twist into the run. Doing so keeps the hose ends from being worked loose by vibration over time. Both ends mate to standard AN flare connections. As always, check that the fitting you are joining to uses the 37-degree AN flare seat rather than a 45-degree or O-ring boss design.