1. This is a bicycle or tricycle general mechanical speedometer, it is a bicycle equipment made of durable aluminum alloy.2. Pure mechanical bike computer, not only has good quality, but also has accurate data.3. It works for 26/27.5/28/29 inch bikes only, be sure to check your bike size before you buy it.4. Our product accessories are complete and easy to install, you can do it by yourself without any effort.5. The must instrument you should need for your bike journey, and you'll find it useful.Specification:Features:This is a bicycle or tricycle general mechanical speedometer, it is a bicycle equipment made of durable aluminum alloy. Pure mechanical bike computer, not only has good quality, but also has accurate data. It works for 26/27.5/28/29 inch bikes only, be sure to check your bike size before you buy it. Our product accessories are complete and easy to install, you can do it by yourself without any effort. The must instrument you should need for your bike journey, and you'll find it useful.Specification:Condition: Brand NewMaterial: Aluminum AlloyColor: BlackSize: Approx. 11 * 8 * 8 cm / 4.3 * 3.1 * 3.1 inWeight: Approx. 333 g Installation Conditions: A quick release lever or a large front wheel clearance is required for installation.Package List:1 * Bicycle ComputerNote: Only the Bicycle Computer, bike others are just Photography Props.