This straight adapter puts an AN10 37-degree male flare on one end and a 3/8″ NPT male pipe thread on the other. It is a reducing combination, which makes it useful where you want the flow and hose availability of -10 AN but the component itself only offers a 3/8″ pipe-tapped boss, such as a pump inlet, filter head or cooler port. Remember that the smaller NPT end governs the real flow through the assembly, so it is a sensible choice for feeding a bigger hose run rather than for chasing maximum flow. Seal the tapered NPT threads with a fuel-compatible sealant; the AN flare seals on its own.