Round Bicycle Mechanical Speedometer Cycling Odometer Stopwatch BDLIV : This mechanical cycling computer won't need to use any battery,is designed with clear dial and can provide accurate data. Fit for using on 26\/27.5\/28\/29 inch bikes only,please check your bike type before purchase. It is easy to install,you can install it easily without using any special tools,the installation won't harm your bike. Made of strong and tough aluminum alloy,it can last for a long time,not easy to be worn out or damaged. It is powerful and useful,it can display speed,distance,so you can have a better control on your cycling speed. Specification: Material: Aluminum alloy. Color: Black. Size: 11*8*8cm. Package Include:1* Cycling Speedometer