A straight adapter putting an AN12 37-degree male flare opposite an M12*1.5 male metric thread. The size difference is deliberate: -12 AN is a large hose used for oil coolers, dry sump lines and high-volume fuel plumbing, while M12*1.5 is a small metric port typical of European and Japanese housings, drain bosses and sender locations. Use this where a -12 run must terminate at a modest metric fitting, accepting that the M12 thread sets the effective bore of the joint. The AN flare needs no sealant when torqued against its mate; the metric side seals with the washer or O-ring the port was designed for, never with PTFE tape.