The Mountain Mirrycle<p>mounts in minutes with the wrench that</p><p>is included. The mirror is a 3" round,</p><p>convex glass mirror with a wide field of</p><p>view. The mirror is adjustable to any</p><p>viewing angle. </p><p> </p><p>Fits inside handlebars with 13.75mm - </p>22.5mm (.54" to .875") inside diameters