Abstract: A plurality of arcuate grouping contacts and a plurality of strip contacts are formed in an annular array in opposed spaced relation with each other on two insulation layers. A control key is disposed in opposed position to the annular array of contacts on the side of one of the insulation layers opposite from the other of the layers, and an annular elastic member is interposed between the undersurface of the control key and the annular array of contacts whereby a portion of one of the insulation layers is displaced toward the other of the insulation layers depending upon the direction and magnitude of a force applied to the control key to bring the grouping contacts corresponding to the direction of the force into contact with one or more of the strip contacts.