A straight adapter with an AN12 male 37-degree flare on the hose side and an AN10 male O-ring port thread on the component side. It suits oil and fuel systems that run AN12 hose for low restriction but terminate at coolers, pumps, filter heads or tanks tapped AN10. Being a single size step, the loss through the joint is modest. Sealing takes place at the O-ring on the machined boss face rather than on the threads, so no tape or paste is used, the adapter can be clocked before final nip-up, and the connection comes apart cleanly at service time without damaging the casting.