Abstract: Unusually long life and reliability in a selector switch are achieved by providing long-wearing components which, in turn, contribute to an essentially dust-free environment for the contact portions of the switch. Materials of all parts produce a minimum of abrasion dust and the conformation of the housing structure prevents the entry of exterior dust. A binary coded cam having multiple cam sections causes sliding contact between spring type contact elements and shorting bars. The rotary element and the two main housing portions are molded of a highly wear resistant, low friction material. The detent mechanism is separated from the contact elements and the metal housing clamp locks the housing portions in the mated position, and helps to seal the housing against exterior dust. All components provide maximum life expectancy and low wear properties.