A. Aluminum alloy material: It is suitable for many types of bicycles, like road bikes, mountain bikes, fat tire bikes, etc. It comes with tools and installation instructions, and is relatively easy to install. The size of the frame body is adjustable. B. Dimensions: The rack is about 55 cm long and 14.5 cm wide; the panel is around 35.5 cm long and 14.5 cm wide. (Seat tube diameter: 2.2 - 3.3 cm / 0.85 - 1.3 inches), which can be adapted to various bicycles and is easy to install. It is quite suitable for use with hanging bags, backpacks, baskets, etc. C. Package contents: 1 frame body, 6 support rods, 7 screws, 2 rubber washers, 2 formed washers, 1 rearview mirror, 1 installation instruction, 1 set of installation tools, 1 keychain (gift). Note: Installation tools are provided. If you don't receive them, please contact us for re - issuance. D. Safety performance: The red rear reflector can enhance visibility during night rides and help ensure your safety when riding at night. E. Load - bearing capacity is approximately 110 pounds. It is an adjustable bicycle carrier rack made of aluminum alloy that can be used with many types of bicycles. The rack is about 55 cm long and 14.5 cm wide; the panel is around 35.5 cm long and 14.5 cm wide.