M-Wave Pole Position training wheels With these training wheels you offer your child the opportunity to learn to ride a bike safely. The wheels are easy to assemble. In addition, they are adjustable, so they can be used up to twenty inches. The set also includes brackets that prevent the wheels from turning. You clamp these against the horizontal frame tube. The set comes in a blister pack. Specifications: Color: silver, black, white Frame material: steel Tire material: rubber Rim material: plastic Mounting materials included Wheel size: 12-20 inches