Solid, all-terrain rubber tires with self-lubricating nylon bearings ideal for rolling across uneven surfaces indoors or out. Features a sturdy, rust-resistant powder-coated steel frame. Wide wheel base for stability. Nonslip pedals with no exposed hardware for safety. Heavy-duty rubber handgrips, recessed no-pinch hub design and comfort back support. Some assembly required. Small supports users up to 70 lb, is recommended for ages 3-5, and measures 25"L x 16"W x 26"H; 33 lb. Large supports users up to 90 lb, is recommended for ages 4-8, and measures 21"L x 20"W x 28"H; 30 lb.