Abstract: A control includes a shaft rotatable between a plurality of positions. The base of a spring is fixed relative to the shaft and arms extend from the base parallel to the shaft. Each arm includes a resilient finger and a nose projects from each finger toward the shaft. The noses are 180 angular degrees apart and at different positions longitudinally of the shaft. A cam rotates with the shaft and the noses are biased against the outer surface of the cam. A plurality of recesses are angularly spaced apart around the outer surface of the cam in pairs which are spaced 180 angular degrees apart. One of each pair of recesses is longitudinally aligned with one nose and the other of that pair is longitudinally aligned with the other nose. The noses and recesses provide a detent when the recesses of a pair are angularly aligned with the noses with which they are longitudinally aligned and do not form a detent when the shaft is substantially 180 angular degrees removed therefrom.