Sullivan Re-Invented the Wheel! Their SkyLite Wheels Provide Strength and Improved Balance. FEATURES: They are Have a Foam Core which makes Them 40% to 50% Lighter Than most Wheels. It offers Low Bounce for Smoother Landings. Durable Rubber Skin for More Rugged Construction. They are Designed to Provide More Strength and Improved Balance. INCLUDES: Two 2" Diameter Skylite Wheel COMMENTS: The nylon hubs are overdesigned, and can be drilled out to the next largest size.