Excellent, easy to make, just needs a couple of strips of inch by eighth aluminium bar, drilled and then bent in the vice and a perch. I started doing this because the ready made ones you can buy here just had acrylic supports which quickly got broken by us humans bumping in to them. Because Caspers cage has an arched top I put this one on the front. We call it his balcony and it his favourite place to be (apart from on a shoulder).
I did smooth off all the edges and then purely for my own satisfaction, buffed it up to a nice shiny finish. Thinking that the thin metal might be a bit uncomfortable on his feet when he walks along it I put some plastic edge cover pieces on. Casper didn't see the need and soon had the covers shredded all over the floor.