Product review (5 stars): Seems To Do The Job
It seems that fridge filters have shot up unbelievably in price.  I tried this bargain brand as a substitute for the big-name brands, and it seems to work well.  Certainly, the water tastes as good as before.  But unless you're a chemist, you won't know how the water compares in actual quality.  If you're getting your water from a reputable city supply, my guess is, you'll likely be safe.  (But I'm no expert.)