Usage Tips:Sturdy Material: Bike training wheels for kids are made of ABS wheels and metal. Bicycle auxiliary wheels are durable, non-slip and wear-resistant, providing stability, helping children ride bicycles, and making children enjoy the fun of riding bicycles. .Safe & Auxiliary: Your childrens safety is our top priority. Heavy duty training wheels help beginners to maintain balance and provide greater safety and stability until they learn how to ride a bicycle. Without holding the saddle, you will make sure your children's safety. .Universal Size: Our kids bike universal training wheels suit for 12 14 16 18 20 inch children's bicycles, which meets the needs of children to learn to ride when they grow up. Please check whether these wheels are compatible with your bicycle. .Flash Design: Our toddler training wheels are non-slip and noise-free. Especially with the flash function, children are more interested in riding at night. Bicycle stabilizer wheels are great helpers for your childs first bike class .Easy to Install: 20in training wheels kit includes two shoulder bolts, two nuts, two washers, limit spacer, two vertical bracket arms and two wheels. By two wrenches to install the training wheel on the rear wheel of the children's bicycle, and you can adjust the distance of the vertical bracket from the ground.