Description: 【Universal Fit】: Designed to fit a wide range of children's single-speed bicycles, including sizes 12-20 inches. This versatile compatibility ensures these training wheels can support your child as they grow and graduate to larger bikes 【Heavy Duty Steel and Stable Design】: Engineered for maximum stable, our training wheels feature thickened steel support brackets with a reinforced triangular structure. This robust construction provides exceptional stability and balance, preventing rollovers and giving you peace of mind while your child learns 【Quiet, Non Slip Rubber Wheels】: Enjoy a quiet ride! The wheels are made from soft rubber that absorbs shocks and reduces noise. They are also designed to be non scratch, making them ideal for both outdoor adventures and indoor practice on delicate floors 【Effortless Installation】: These training wheels are incredibly easy for parents to install directly onto the rear axle of the bicycle. All necessary hardware is included, and no special tools are required for a secure and reliable fit 【Build Confidence and Master Biking】: The aid for any beginner, these wheels provide the crucial support needed to overcome the fear of falling. They help your child build balance and confidence, allowing for a fun and smooth transition to riding independently on two wheel Specification: 13cmx13cm/5.12inchx5.12inch Package Includes: 1 Pair of Kids Bicycle Training Wheels Note: Please allow slightly errors 1-2cm differences due to manual measurement.