High Sierra Carry-On Wheeled Backpack It's three bags in one! Use it as a wheeled bag, as a backpack or as a day pack. Special built-in, high-density foam structure helps maintain the bag's shape while minimizing weight. Padded backpack straps stow behind the main compartment's zippered padded back panel. Padded, S-shaped shoulder straps with integrated cell phone pocket on the removable day pack. Removable front day pack with zippered accessory pocket has a back strap to allow pack to slip over the extended handle of main bag.