Product review (4 stars): Much cheaper than the first-party alternative, just as good
We bought a new refrigerator with a water dispenser, and love the convenience.  When it came time to replace the filter the first time, we were not in love with the price for the manufacturer's filter.  Luckily, we stumbled upon Water Sentinel.  The filter is a fraction of the cost, and does the job just as well.  I'll be happy to continue buying them going forward!