Wheel center caps are considered to be accessories but they can also be called performance parts since they improve the performance of the wheel. They are available in a number of varieties depending upon the number of slots, openings, holes or spokes in the wheel. They are available in a variety of colors and shades like Chrome, Silver, Chrome plastic, Polished, Machined finish, Plastic, Polished with black center, etc. They are made of plastic or various other mixed materials. Their price ranges from $20 to $70. They are mostly used to maintain the value and appearance of the vehicle. Replacement of missing or worn out center caps adds to the value of the vehicle, especially when it is to be sold. USA, Taiwan, China, and India are the leading manufacturers.