Rim spacers are used to reduce the ET of the rim, in other words, to make it more exposed within the wheel arch. Wheel spacers are sometimes necessary for the correct installation of the rim. Their size is matched to the hub diameter and bolt pattern. Wheel spacers are usually made from aluminum and can be divided into three basic types:
through-hole with no collar (up to 5 mm wide),
through-hole with a collar (width between 5 and 15 mm),
bolted to the hub (width over 20 mm).