A straight AN4 to M10*1.25 adapter machined from SUS303 stainless steel. The stainless material is the distinguishing feature here: it holds up far better than plated steel where the fitting is exposed to road spray, brake fluid, coastal air or repeated wash-downs, and it resists galling against other steel components. M10*1.25 is a fine metric pitch used on turbo oil feed bosses, sender locations and small metric hydraulic ports, and it must not be confused with M10*1.0 or M10*1.5. On the -4 AN side it suits turbo oil feeds, gauge and pressure sender lines and other low-volume, high-pressure circuits. The 37-degree flare seals dry on metal contact.