A straight stainless hose end that takes -3 braided line and presents a female AN4 connection, combining the hose termination and the size step into a single machined body. That matters on brake and clutch circuits, where every extra threaded joint is another potential leak point and another thing to bleed air out of. Use it where a component was built with AN4 ports but the line size you need is -3, which happens often on adapted calipers, clutch masters and pressure senders. SUS303 stainless suits the corrosive environment around brake components. Confirm the mating male AN4 fitting uses a matching seat form before assembling the hose.