Product review (5 stars): Works great even on my old KitchenAid fridge.
Fits our 15 year old KitchenAid refrigerator no problem.  The hardest part was turning off the water to the service line, then bleeding the air out of the system again after the replacement.  I had my 7 year old help, and he was concerned about the spurting and burbling during the first quart or two of water coming through the fridge filter.  That's normal... don't forget to run the water through the water dispenser before first use!