Abstract: A fan includes a base and an impeller rotatably mounted on the base. The base protrudes a tube outwardly therefrom. The tube defines a receiving hole therein for receiving a bearing. The bearing defines a bearing hole therein. The impeller protrudes a shaft therefrom towards the base. The shaft is rotatably received in the bearing hole. The fan further includes a gasket located at a bottom of the bearing and clipped on a free end of the shaft. The gasket includes a first surface and an opposite second surface. The first surface is a smooth surface and facing directly the bottom surface of the bearing. The second surface is a rough surface relative to the first surface. At least one of the first surface and the second surface is provided with a mark to differentiate the rough second surface from the smooth first surface.