Bicycle mirrors provide you with the essentials when riding. Because the product is a glass product, If there is any damage, please contact us through Amazon customer service No tools are needed. Just use the rubber strap buckle to install it, and it will be installed in a few minutes. But please pay attention! ! Be sure to install the buckle tightly according to the size of the handlebar to prevent the rearview mirror from shaking due to bumps during riding! Glass mirror and silicone rubber belt support a clear view and fastness. Applies to mountain bikes, kids bicycle，off-road vehicle and fixed gear bikes. Adopt high-strength ABS material and stainless steel screw, give you shatterproof chromeplated mirror, offer you high-definition views, also ideal for decoration. Base with 360 degrees full rotation and could adjust to any direction to help you watch every direction of your back.