●Material: Plastic Iron ●FITS 12-20 INCH BIKES: This bicycle training wheel is suitable for 12-20 INCH bicycles. Some bikes cant be installed ●Manor Mode Design: The wheel reduces rattling noises unique to training wheels. You can easily practice in a room without worrying about noise ●Use: Training wheels for children bicycles. The simple design allows it to be mounted on most infant cars and childrens cars ●EASY TO INSTALL: Comes with parts for easy installation. If you have any questions, please feel free to email us at any time