ZUCA Sport Artist Bag and Frame with Built-in Seat with Four Large Stacking Utility Pouches Aluminum alloy frame that is light, super strong and rated to hold up to 300 lbs. - doubles as a built-in seat Removable, hand washable, replaceable insert bag is made from premium water resistant 600D polyester The dual wheel system climbs curbs and stairs with ease Magneto dynamic flashing 4 polyurethane wheels absorb shock and make for a seriously silent ride Chrome plated, rust resistant screws