Zuca Bag Rebel - Black Frame Inspired by aerospace technology, the aluminum alloy frame is light, super strong and rated to safely support up to 300 lbs Magneto dynamic 4" polyurethane wheels absorb shock and make for a seriously silent ride The removable, hand washable, Insert Bag is made from premium water resistant 600D polyester Award winning high quality travel case with wheels, and a seat to relax on (when you get tired). The dual wheel system climbs stairs and curbs with ease