Multiple transport methods for flexible carrying: adjustable shoulder straps and hand rings support handheld, singleshoulder, and rearaccess use, making it easy to carry and access your rear rack bag during outdoor activities. Enhanced visibility for safety: brightness reflective strips are embedded to reflect light in lowlight conditions, improving visibility and safety after dark. Practical and organized storage: 8.6L threedimensional design with a main compartment for water cups, tools, and clothing to keep cycling items organized; a front interlayer holds keys and cards for convenient access. Wide compatibility and secure mounting: secures onto rear racks or frame tubes and fits mountain bikes, road bikes, and electric bikes to meet diverse cycling demands. Use scenarios: Daily commuting: quick access to water cups, tools, and essentials while keeping items organized. Weekend rides or training: ample space for clothing changes and tools, with separate keys/cards for easy reach. Long trips on various bikes: reliable rear rack or frametube mounting for mountain, road, or ebike setups, ensuring you have gear within reach.