Patented rugged steel frame construction for strength and durability. Double front swivel wheels for maneuverability and double rear wheels for stability. Detachable extra-large water-resistant polyblend canvas bag with fitted cover for privacy and protection from the elements. Compact folding for convenient storage in tight places. No complicated assembly or tools required; simply click on the front wheels and go. Bag / liner does not contain PVC and is free of harmful phthalates