Product review (3 stars): Ok while they last....
These switches are poorly made and wear out fast.  It's no more than a potentiometer but every time you turn the knob you are slowly cutting through the ribboning on the circuit board.  Bottom line is these will fail about every year for most families.  Turn the selector switch as infrequently as possible and hope you get more than a year out of these.  I'm on switch #4 in six years.......