An assembly having a soft-touch user interface for controlling the operative position of a device which controls the flow of air into the passenger compartment of a vehicle is provided. An occupant of the vehicle operates a first member of the assembly at its outer soft-touch, surface layer to cause the first member to rotate about an axis. A second member of the assembly rotatably supports the first member. A portion of a structural substrate of the first member is configured to couple the first member to the device. The substrate and the second member have a pair of annular faces that oppose each other and are oriented to face axially along the axis. A portion of a biasing member projects outwardly from at least one pocket in one of the faces to frictionally engage the other face and prevent undesired rotational movement of the first member.