Product review (3 stars): Pricy little object that's necessary but it works well
Of a necessity this is a REQUIRED product of the Frigidaire refrigerator that we own when we bought this house.  The owner never told us, nor has he changed the filter, so this is the second one we bought and Amazon is A LOT CHEAPER than the big box stores.  Every six months you have to change this.  Supposedly it removes a bunch of contaminants, but really, who knows unless you get it tested, so honestly you have to take their word for it that it does.  For $30 x 2 x the life of the refrigerator it adds up!  I guess the previous homeowner didn't count on that when he bought it...