An improved structure of a cable winch used in vehicle is disclosed. The lens body includes an optically effective portion and a peripheral portion surrounding the optically effective portion. Thus, the document can not be forged by replacing one element with a similar element from another document. Next, a trench and a contact hole are formed by etching the dielectric layer so that the upper surface of the transistor is exposed. The alternate flow passage is defined between an inner and outer wall of the single housing, while the fan is mounted within the inner wall.