Yosoo Adjustable Kids Bicycle Bike Training Wheels Fits 12" to 20" Durable, and includes includes everything you'll need to install the training wheel to a bike for that 12-20 inch stable training wheels.Help your young ones learn to ride safely by installing Training Wheels on their two-wheelers. The training wheels are carefully crafted for easy installation and excellent reliability. Plus, they roll super smoothly, too. Thanks to 4 1/2-inch diameter wheels with hard-rubber tires The Training Wheels fit children's bicycles sized 12" to 20" so you can move them from bike to bike as your kids grow, too. Includes hardware, screws and nuts