Big AN20 hose has a large minimum bend radius, so getting it to leave a port and change direction cleanly usually needs an angled fitting rather than brute force. This 45-degree hose end gives a gradual turn that keeps the bore open and reduces strain where the hose meets the fitting — useful on dry-sump tank connections and large cooler and fuel plumbing. The swivelling AN20 nut lets you make up the joint without winding the hose. It is a reusable socket-and-nipple design. Given the size, assemble it in a vice with soft jaws and use two spanners on the final joint.