The described wheel cap comprises a wheel cap element (2) which can be rotated with a wheel rim (12) and a fixed disc (3) which is coaxially rotatable with respect to the wheel cap element, the rotational friction being reduced by a bearing (6) and is isolated in terms of rotation from the rim by a lateral load (9) which provides a centre of gravity on one of its circumferential sides. The fixed disc (3) can bear different images or symbols and thus serve for example as an advertising surface. The wheel cap described also comprises a transparent housing cover plate (8) for covering the fixed disc, a vacuum chamber (13) being formed between the cover plate (8) and the wheel cap element (2) for the positioning of the fixed disc. Within the wheel cap element, a device for supplying current to the fixed disc is formed and either a plurality of single-row ballbearings or one multi-row ball bearing serves as ball bearing for bearing the fixed disc against the wheel cap element. <IMAGE>
