Abstract: A potentiometer and switch combination including a rotatable control cap positioned over a potentiometer body to form a housing. The cap is provided with an annular flange which abuts an annular shoulder on the body, either the flange or the shoulder being formed from stiffly flexible, resilient material. The body holds the cap in place by means of a post having a chevron at its upper end which mates with a recess in the cap. The cap is positioned to deform the stiffly flexible, resilient material into frictional sealing relation with its abutting member and thereby seal the interior of the housing. The sealing arrangement also introduces a torque which opposes rotation of the cap. The switch includes a conductive strip held by the body, one portion of the strip forming a first contact and another portion forming a spring detent.