Bicycle Rearview Mirror 360 Degree Rotating Bicycle Mirror Riding Mirror Single Pack Features 360-degree rotatable design, you can rotate different angles according to your own perspective. The base can be changed at 90 degrees, and it can be used at multiple angles, which is convenient to use. High-strength PC durable frame, high hardness, anti-aging, not easy to break. Allen wrench is included for easy installation. Installation instructions: The diameter of the bicycle pole needs to be between 21-23mm before it can be installed. Please confirm the size before purchasing. Parameter Material: PA/PP/Aluminum alloy base/Glass mirror 😁 [Satisfaction First] - Customer satisfaction is our top priority. If you are not satisfied with any of our Kayannuo product, please contact us and rest assured that we will do our best to make it right. Please refer to the size chart images and product descriptions, as well as our customer feedback, to ensure an accurate fit. 360-degree rotatable design, you can rotate different angles according to your own perspective. The base can be changed at 90 degrees, and it can be used at multiple angles, which is convenient to use. High-strength PC durable frame, high hardness, anti-aging, not easy to break. Allen wrench is included for easy installation.