An inverted seat adapter that combines an AN6 37-degree flare with a 5/8 x 18 inverted flare thread. Inverted flare is the original-equipment sealing method for steel hard lines in brake, fuel and hydraulic circuits, and its seat is a different geometry to an AN flare, so the two cannot simply be screwed together. This adapter provides the correct seat on the inverted side and a standard -6 AN flare on the other, so you can transition from factory hard line to braided hose at exactly the point you choose. Both seats seal on metal contact when torqued, so keep the faces clean and free of sealant or tape.