Product review (5 stars): Easy to install
This was a snap to put in (pun intended) I was worried since this was not a sub zero part that we would have issues. It  is a part for other manufactures as well. It is important to know this controls only the light for the refrigerator part only.
I have a 15 year old model 550. The other switch is for the fan. It turns fan off when the door is open.
It took five min. To install. This part has a history of needing to be replaced on old 550 models.