Features1More durable, using high quality environmental protection high strength PP plastic. 2Our products have done static treatment, no scrubbing, maintain the bright and beautiful for a long time. 3These heavy rear wheels provide the necessary safety and stability needed for the first road test of a bicycle, giving your child the best start for balance and confidence without holding the saddle. 4This heavy-duty rear wheel stabilizer helps young students ride their bikes until they have a usable sense of balance. 5Suitable type: suitable for most 12inch to 20 inch singlespeed bikes. With horizontal rear track fork ends, but not for halfhorizontal or vertical drop bikes.SpecificationItem Type: ChildrenBike Training WheelMaterial: metal + rubberColor: blue, pink (optional)Suitable for: 12 "/ 14" / 16 "/ 18" / 20 " children bicycleDiameter: approx. 11.5cm/4.5inchThickness: approx. 1.5cm/0.6inchPackage List2 x Training Wheel2 x Support Bracket1 x Screws Bag