Practical design Size: 24 x 10 x 50 cm. The backpack includes an internal compartment for a water storage bag and can store tablets. It has two outside zippered pockets suitable for glasses and keys. A hidden zipper pocket inside the front pocket holds valuable items such as phones and wallets. With multiple compartments and a large capacity, it easily meets storage needs for outdoor cycling or running. Breathable and comfortable Made from tearresistant, waterproof nylon fabric with a quality zipper. The back panel is padded with breathable mesh and paired with adjustable double straps, ensuring it remains breathable when you are sweating. fit Ergonomic design with a chest strap and waist belt to secure the bag and prevent movement during cycling. Wide mesh shoulder straps help reduce shoulder burden. The waist zipper bag provides support and can store phones, replenish energy, food, and other items. An adjustable chest strap with a whistle is included. Helmet storage and reflective design The exterior zippered bag and two side buckles create space to secure riding helmets and other items. The back features reflective strips to improve safety when hiking in the dark or cycling in mountainous areas. Use scenarios Daily bike commute: store a water storage bag, phones, wallet, and keys in the appropriate pockets; helmet can be secured with the side buckles. Weekend trail riding or running: breathable fabric keeps you comfortable; energy snacks and items can be kept in the waist and front pockets; reflective strips aid visibility in low light. Long day trips or tours: multiple compartments help with organization; the water storage bag supports hydration on the go; helmet storage keeps equipment accessible.