This bag is waterproof and can be used as a bike rack bag, backpack, and shoulder bag. It features large capacity that can meet your daily needs, great forcycling, commuting, hiking, traveling, and other outdoor activities. Features: 3-in-1 design: This bag can be used as a bike rack bag, backpack and shoulder bag, great for cycling, commuting, hiking, traveling, and other outdoor activities. Waterproof: High-quality PVC material and welded seams prevent water seeping into the bag, and the roll-top closure ensures better protection to keep your belongings dry. Large Capacity: Main compartment includes a padded pocket for laptop, and a zipped mesh pocket for valuables; side mesh pocket for small items; exterior zipped pockets for other accessories. Easy Installation: The new mounting system in the zipped pocket makes it easy to attach the bag onto the rear rack of your bike in seconds. Hidden Straps: Thick mesh shoulder straps provide good breathability and comfort when carrying the bag. The reflective strip on one strap increases visibility and safety at night. Specifications: Material: PVC Color: Black / Blue / Red (optional) Size: Approx. 28 * 17 * 48cm / 11 * 7.1 * 18.9in Weight: Approx. 1.3kg / 2.9lb Package List: 1 * Backpack