The holder for an electroconductive contact unit according to the present invention uses a silicon wafer having a laminated structure including a first silicon layer, second silicon layer and silicon oxide film which is disposed between the two silicon layers. For example, different shift schedules may be used for operating with the engine off, operating with the engine running, and regenerative braking. An optically transparent test region is interposed between the conductive lines, and a metallic reflector underlies the test region. The rings can be attached to the stone using anchor, so that the setting cannot be removed from stone unless the stone, a ring, an anchor or combination thereof is broken or, in the case of hooks, removed only with great difficulty or irreversibly damaging the hooks. An electrical conductor is coupled to the conductive material trace at a predetermined location below the upper portion of the bevel.