Wide, high-traction rubber base offers increased stability, with durable rubber T-springs for a lively bounce. Easy to steer with adjustable-height joystick-type handle. Nonmarring on floors. 45"H (114 cm). Small supports users 33-66 lb (15-30 kg); Medium supports users 66-132 lb (30-60 kg); Large supports users 110-176 lb (50-80 kg).