--DURABLE ALUMINUM ALLOY MATERIAL:This product is a bicycle or tricycle general mechanical speedometer, it is a high-quality bicycle equipment made of durable aluminum alloy.--ACCURATE DATA: This cycling automatic pure mechanical bike computer, not only has good quality, but also has accurate data.--SUITABLE BIKE SIZE: This speedometer works for 26/27.5/28/29 inch bikes only, be sure to check your bike size before you buy it.--EASY TO INSTALL: This product accessories are complete and easy to install, you can do it by yourself without any effort.--GOOD BIKE JOURNEY: This cycling computer is the must instrument you should need for your bike journey, and you'll find it useful. Note: Only the Bicycle Computer, bike others are just Photography Props. Specification: Material: Aluminum Alloy Color: Black Size: Approx. 11 x 8 x 8 cm / 4.3 x 3.1 x 3.1inchWeight: Approx. 333 g Package List: 1 x Bicycle Computer