Amazon.com: Columbia Unisex Lightweight Packable Backpack 。Product Details Designed for Casual Water-Repellent Fabric Measurements Dimensions: 31.5cm x 17cm x 61cm (12.4\" x 6.7\" x 24\") Volume: 32L Product Features Adjustable straps let you carry it by the handles or on your back Side pockets for quick access to water bottle and small items Zippered main compartment Trolley-compatible strap Exterior zippered pocket holds small items and doubles as a packable pouch—flip the pocket inside out to stow backpack when not in use Hanging loop lets you easily store pouch