【Compatibility】: The kids bike training wheels are suitable for children's bicycles of 14", 16" and 20", providing the necessary stability for your child's bike. 【Versatile Usage】: These thickened kids bike training wheels are designed to roll smoothly on various surface, including uneven or bumpy terrains, They are compatible with a wide range of scooters and bikes, such as 2 wheel mini push scooters, 3 wheel scooters, children's walkers, and micro scooters.