This mirror seems well designed, with joints of more elaborate mirror as well round mirrors that I already had. This is attached to the handlebar which is a complete error. The diameter of the fixing ring is less than 20 mm, and will absolutely not on ATVs to aluminum handlebars, or on my bike treck carbon handlebar or on the throttle handle on which I was planning to install it. He did not even suitable for my old bike steel, whose basic standard handlebars, as no market, there is still a higher dimension. It is a mistake to Amazon, which should report this problem to the manufacturer. I keep and will do a scam ring tinkering .... For the rest of retro is well done ... .. Bon voyage Retro is essential ...