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.Removable front day pack with zippered accessory pocket, side water bottle pocket, MP3 player headphone port and has a back strap to allow pack to slip over the extended handle of main bag. Padded, S-shaped backpack straps on the removable day pack. Removable day pack organizer has zippered mesh pocket, smart phone pocket and key fob. Tow-strap, for attaching an extra bag, and an identification holder hide-away in a back pocket. Inline skate-style wheels, in protective corner-mounted housings with unique integrated bridges that keep the bag rolling true. Kick plate between the wheel housings protects the bag from abrasion. SURE-GRIP handles tuck down flat when not in use. Reflective piping for added safety.