1. [Universal Diameter and Compatible Sizes] Are you still worried that some bicycle training wheels can only fit one or two sizes of bicycles? Don't worry. The training wheels with a bracket that has 5 different mounting holes can perfectly meet your needs to install them on 12 - inch, 14 - inch, 16 - inch, 18 - inch, and 20 - inch bicycles. The round and lovely appearance is well - matched, just like a blue lollipop, bringing gorgeous colors to your child. (Note: Not suitable for变速 bicycles.) 2. [High - quality PU Material Thickened Wheels] We've always been looking for bicycle training wheels that are quiet, wear - resistant, and can also play a shock - absorbing role. The training wheels made of high - quality PU material just meet these requirements. At the same time, the 2.5 - centimeter thickened wheels (0.5 centimeters thicker than ordinary training wheels) can reduce bumps, make cycling easier and more labor - saving, and provide a higher level of comfort. 3. [Double - layer and Larger Washers] After optimization, the double - layer high - carbon steel of this training wheel has been tested to be quiet and durable during use, extending the service life of the wheels. In addition, we've specifically enlarged the washers so that they can completely cover the corresponding parts. So, even if your child has been riding for some time, there's no need to worry about the training wheels suddenly falling off and causing the child to suddenly fall to the ground. The child can ride safely and grow freely. 4. [Thicker Bracket, Stronger and More Durable] Have you ever encountered the situation where the bracket of the bicycle training wheel is deformed or even broken? Don't worry. Considering this, we've designed a training wheel with a bracket thickness of 3 millimeters, which is 20% thicker than ordinary brackets and has stronger support ability. Therefore, it won't deform or break. Your child will be safer when enjoying the fun of learning to ride a bicycle. 5. [Easy Installation] Equipped with a wrench, you can complete the installation. The locking buckle is a great helper for fixing the bracket and the bicycle. It couldn't be simpler. At the same time, we recommend that when the bicycle is parked, the training wheels are about 5 millimeters from the ground, which helps the child master the sense of balance while riding. Color: Black Material: Plastic Package Contents: 2 wheels 1 wrench 2 sets of screws and nuts 2 cushions Only the above package contents are included, and other products are not included. Note: Light and different monitors may cause a slight difference between the color of the product in the picture and the actual item. The measurement error is allowed to be ±1 - 3 centimeters.