This AN8 tee combines male 37° flares on the straight run with a female swivel on the side port. AN8 handles fuel feed on higher-demand engines, oil cooler runs, breather and catch-can plumbing and pump returns, and a tee of this size commonly splits a feed between two consumers or merges two returns into a single line back to tank. The swivelling branch makes routing far easier, since the hose can be clocked into place after the run is tightened rather than being twisted. Bracket the tee where you can and confirm all three sealing cones are clean before assembly.