1. It has enough space, measuring 32 x 28 x 17 cm. It has multiple compartments. The high - quality material is durable and waterproof PVC. The adjustable Velcro straps allow for quick and easy assembly. 2. It features an elastic mesh pocket, side pockets, and an inner pocket. For the black one, the size is 2 x 2 x 8 x 17 cm. The material is durable and waterproof PVC. The installation types include bike installation and seat installation. 3. This multi - functional bag is very suitable for daily commuting and short - distance trips. It can be used in multiple ways, whether you fix it on the luggage rack, use the hidden shoulder straps, or carry it by the handle. 4. With a size of 32 x 28 x 17 cm, it has enough space to hold all your essentials. It has multiple compartments, including an elastic mesh pocket, side pockets, and an inner pocket, which facilitates the organization of your items. The high - quality PVC material ensures that your items stay dry and are protected from rain and dirt. Tool - free installation can be easily achieved using the adjustable Velcro straps, making it compatible with most bike racks, including those on mountain bikes and road bikes.