An AN4 male flare, an AN4 female swivel and a 1/8″ NPT female branch in a single machined body. AN4 is the workhorse size for fuel pressure regulator return lines, turbo oil feeds and gauge plumbing, and this adaptor lets you monitor any of them without adding a separate tee and extra hose. The 37-degree flare ends thread onto standard AN4 hose ends and adapters, and the female end swivels so you can orient the NPT port where the sender clears the bodywork. Seal the tapered NPT thread with PTFE tape or a fuel-safe sealant, keep the tape clear of the first thread, and support the body with a spanner when tightening the sender.