Recommended Range of Usage: It can be used for hlebars with a diameter of 21-26 mm . It can be used perfectly for 22.2mm diameter hlebars.We Can Use It For Mountain bike Hlebar, Leisure bike hlebar. 360 Degree Adjustable: our bicycle rear view mirror can be adjusted to any angle according to your needs, without blind spots in the line of sight. Long arm coverage is better: The environmentally-friendly safe long arm ensures better coverage of the field of vision, making your riding safer. Installation Stability: high-hardness aluminum alloy base, hard plastic support, the rearview mirror will not move during riding. The sturdy structure ensures that the mirror can be used for a long time. Even during downhill riding, the mirror will not shake, crack or break. Very Easy to Install: They have nuts to lock them in position so they dont move. Adjust the mirror based on our suggestion,so you can have wider view behind you while riding.