Product review (5 stars): Exactly what I needed
This was incredibly easy to install in my Whirpool Fridge.  I followed the directions that came with the replacement cartridge (and also consulted my fridge's user manual) and the entire process took less than 5 minutes.  All you have to do is remove the old one, install the new one, and then run a gallon or two of water through the filter and it's ready to drink!  The directions said to turn off the water to the fridge before starting the process, but I didn't (I'm such a rebel) and it turned out fine.  I will say that your old cartridge will leak, so be careful with it when you take it out!

The water tastes clean and delicious.  Highly recommended!