Big 24" (61 cm) dia platform has over three times the area of a 12" (31 cm) scooter, with room for up to three students! Recessed handles allow easy control and protect fingers. Indoor/Outdoor scooter features heavy-duty 4" (10 cm) dia all-surface wheels. Indoor scooter offers 2-1/2" (6 cm) dia nonmarring, thermoplastic-rubber wheels. Both have all-metal, ball-bearing casters for the ultimate in maneuverability. Each scooter features a built-in fitting for accessories for UltimateScooter™ Basketball, Flag Tag™, Ball Launcher™, Ring Toss™, and Disc Fling™! Set of 6 includes 1 of each Rainbow® color. Patented.