1、Thin TPU Film Coating: Made of 0.1mm TPU film, a thermoplastic polyurethane elastomer rubber, this material combines the properties of rubber and plastic, offering durability, oil and water resistance, wear proof, and flexibility. 2、Downward Folding Closure: Unlike traditional zipper closures that leaks in rainy conditions, the downward folding closure design ensures that the opening is not directly exposed to rainwater, making it more waterproof. 3、High Reflective Glass Bead Coating: By applying high refractive glass beads using a coating process on the fabric surface, this bike rack bag reflects light under illumination, enhancing visibility in low light conditions. 4、Double Waterproof Guard: Featuring a waterproof layer above the waterproof zipper, this bike storage bag offers double waterproof prevention to keep items inside dry and protected from rain. 5、Convenient Back Handle: With a back handle design, this trunk bag allows for easy carrying and ensures the safety of items, whether carried by hand or worn over the shoulder. The stylish appearance adds to the convenience and ensures item safety. Item Type: Bike Rear Rack Bag Material: 840D Nylon Coated TPU Waterproof Film Capacity: 18L 1 x Bike Rear Rack Bag