I had a lovely pair of UFO ones before getting the original Yamaha / Acerbis, they were made out of hard plastic with a very nice carbon look but... they didn't have a metal spine like the Yamaha ones have and unfortunately they were no match for the transit vans mirrors in the traffic so I snapped both of them within a couple of months

The original Yamaha instead are knackering vans mirror like nobody's business and they have more than revenged the demise of my pretty UFO's that fought and died in the traffic.