30-degree push-on hose end in AN4 (-4), pushing straight onto socketless hose and gripping the barb without a clamp or crimped socket. AN4 is the smallest size in the range, so it lands on gauge and sender feeds, vacuum and boost reference runs, small breathers and low-volume returns. Thirty degrees is the gentlest correction available, for when a straight fitting just fouls a bracket but a 45 would swing the hose too far off line. It moves very little volume by design, so keep it off anything that has to shift fuel or oil in quantity. Ordinary rubber hose will not grip the barb correctly, so use hose specified for push-on ends.