For bicycle training wheels in the from 16 in to 24 in. Stainless Steel (leg) PVC + rubber (wheel) 5 in wheel Product Color, about Size Item Color May Vary Depending on the type of display, actual product may vary slightly from the product image. This listing for the specification, improved the design of the logo, etc., may be altered. In addition, the manufacturers to reveal the answer your questions about the dimension and a personalized fit and you are not the actual product. Thanks for your understanding.