This straight adapter joins an AN4 37-degree male flare to an M10*1.50 male metric thread. The 1.50mm pitch is the coarse M10 thread and is a different fitting to M10*1.0 or M10*1.25, so identify the port pitch before ordering; a mismatched pitch will start by hand and then destroy the thread. M10*1.50 appears on numerous metric castings, drain and feed bosses and sender positions. On the AN side, -4 is the size used for turbo oil feeds, instrumentation lines and small return circuits. Seal the metric end with the washer or O-ring the port requires, and torque the 37-degree flare clean and dry.