●【Expandable Large Capacity】Efficiently organize your essentials with a main compartment, 2 side pockets, a top zip pouch, and 2 inner mesh pockets. Its standard capacity is 20L, and it can be expanded to a capacity of up to 46L. ●【Multi-Layer Crash Protection】Ensure the safety of your belongings with the durable hard shell construction. The removable interior thicken pad protects delicate items and reduces shock. It is suitable for storing digital products such as cameras and other valuable items. ●【Protection Against Water Leakage】The Waterproof Oxford Cloth is designed with a splash-proof surface and features an interior made of waterproof material, effectively preventing any water leakage. ●【Tool-Free Installation】Easily install and remove the bicycle rear seat bag using the 5 adjustable hook and loop fastener straps. It fits most bicycle racks, including mountain bikes, road bikes, and electric bikes. ●【Versatile Usage Scenarios】The adjustable nylon shoulder strap allows for easy installation and removal. Carry the bike pannier on your shoulder or by hand when not cycling. Suitable for various situations such as cycling, commuting, and traveling.