STREAMLINED DESIGN: The aerodynamic shape of the bike top tube bag is wind-proof, which effectively reduces drag and ensures smooth riding without rubbing the knees, making the ride more comfortable.WATERPROOF & DURABLE: The bolt on top tube bag is a TPU coated 840D nylon construction, seamlessly welded and waterproof zipper protects the contents from rain/splash. Wear-resistant materials and reinforced sidewalls prevent wear and deformation.SPACIOUS ORGANIZATION: The size of the black bicycle top tube bag is 9.1 x 2.6 x 3.9 inches, which is large enough to store a phone, wallet, keys, repair tools, inner tubes, mobile power and energy bars, and more.TOOL-FREE INSTALLATION: Three heavy duty Velcro straps are included in the package of the bicycle frame bag, and the installation position is adjustable by itself. In the absence of tools, it can be securely attached to the bike frame in a few seconds.After-sales service: If you have any questions about usage, please feel free to contact us.