This straight adapter carries an AN10 37-degree male flare and an M16*1.5 male metric thread. M16*1.5 is a mid-size metric port found on oil filter housings, cooler take-off plates, turbo drains and transmission cooler bosses, and it pairs sensibly with -10 AN hose because the two are reasonably matched in bore. That makes this a good choice for oil cooler feed and return lines where you want the metric port plumbed without adding an unnecessary restriction. The AN flare seals on its 37-degree face and requires no sealing compound. Confirm whether your metric port seals on a washer, an O-ring or a cone before fitting, as those are not interchangeable.