Center cap

Early center caps for automobiles were small and primarily served the purpose of keeping dirt away from the spindle nut and wheel bearings of vehicles.

[1] Center caps are often found on new cars to hide the lug nuts, and/or the bearing.

The rest of the wheel was originally of wood or many fitted metal parts.

[2] In modern times, center caps are both metal and plastic, and are typically used with aluminum alloy or styled steel wheels.

Some full wheel covers use removable center caps, typically those retained by lug nuts, with the center cap's purpose to hide the lug nuts that are securing the wheel to the vehicle's hub.