The universally adjustable bicycle rearview mirror can be adjusted 360 to the desired angle, razor-sharp, anti-reflective, impact-resistant and anti-glare, The viewing angle is more comfortable and you can see things behind you clearly.Bicycle rear view mirror Universal left and right mounting possible. Applicable holes in the handlebar inner diameter must be between 18-22mm and compatible with 90% bicycles, mountain bikes and road bikes. The mirror diameter of the bicycle rearview mirror is 7cm/2.75inch. With a clear convex mirror, the field of view is wider, so you can see the surroundings better. Improve bike safety. Even if you ride with family and friends, there is no more congestion. Whether you're going to work, riding your bike with your friends at the weekend, or driving alone, an effective rear-view mirror is essential. This mirror is made of high quality material with durability and almost non-deformation appearance. 1. Connect the expansion screw and the mirror together (do not tighten the screw) 2. Remove the handlebar plug and insert the expansion screw into the handlebar hole 3. Turn the screw to tighten the bike mirror. 4. Tighten the stretch and adjust to desired position. HD, impact resistant, super clear, no distortion High quality acrylic lens and durable frame 360 adjustable viewing angle Fits handlebars from 18mm to 22mm Easy installation with 5mm hex NOTES: 1.Please remember to remove the surface protective film before use 2.This mirror is universal and suitable for both the left and right side.