A straight adapter joining an AN10 37-degree male flare to an M18*1.5 male metric thread. M18*1.5 is a substantial metric port size, typically found on oil galleries, cooler sandwich plates, sump bosses and larger sender locations, and it suits -10 AN hose well because neither end chokes the other. Pick this combination for oil cooler circuits, dry sump plumbing or high-volume fuel work where you want the flow of -10 hose carried right through to the component. The AN end seals metal-to-metal when torqued; the metric end must seal the way the port was designed to, usually against a washer or O-ring rather than on thread sealant.