About this item 2.Compact and light; Recommend to use on the right side Due to different producing batches, product details might be a little different. If you minding the difference, please buy it carefully. 1.Handlebar diameter between 20-23mm is suitable for installing the bell Any Questions,feel free to contact us. We will try our best to solve any problem you meet. 4.A screwdriver is packaged with our bicycle bell to help you set up easily