Radio Flyer Replacement PLASTIC Rear Wheel/Tire - for TRICYCLE / BIKE Only Sold Individually - ONLY for replacement on Radio Flyer Bikes / Trikes Listed ** NOT COMPATIBLE WITH RADIO FLYER WAGONS ** For use on Radio Flyer Tricycles Models: 4-in-1 Trike (#811), Steer & Stroll Trike (#51), Steer & Stroll Trike (#51V), Steer & Stroll Trike (#51T), and Pink Steer & Stroll Trike (#51TP) Outer Diameter: 6.25", Shaft Diameter: 10mm (0.4")