WITH STEEL WHEELS AND HEAVY DUTY BRACKETS, THESE TRAINING WHEELS FROM GIANT OFFER A STRONG STABILIZER FOR THOSE A LITTLE WOBBLY ON THE BIKE. SUITABLE FOR WHEEL SIZES 12 INCH TO 20 INCH, THESE ARE IDEAL FOR KIDS LEARNING TO RIDE. BEING HEAVY DUTY, THEY CAN HANDLE SLIGHTLY HEAVIER/OLDER KIDS COMPARED TO A PLASTIC WHEEL.