A knob for an instrument panel is provided having a body portion, a first end portion adjacent to the body portion, and a second end portion adjacent to the body portion and defining a generally wave-shaped surface. The wave-shaped surface includes a plurality of peaks and a plurality of troughs, the peaks extending away from the body portion in a direction generally parallel to a longitudinal axis of the body portion. An adjustment assembly may also be provided having a first contact member with a contact portion, a second contact member with a contact portion, and an adjustment member with a plurality of protrusions. The protrusions are configured to selectively engage the contact portion of the first contact member and induce an electrical connection, and to selectively engage the contact portion of the second contact member and induce a second electrical connection.