45-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. Forty-five degrees is the most-used angle on any build, steering hose around brackets, rails and pulleys while keeping the bend radius easy. It moves very little volume by design, so keep it off anything that has to shift fuel or oil in quantity. Push-on assemblies suit low-pressure lines, so keep them off pumped brake or clutch circuits.