Product review (5 stars): They work great
We've been using this exact brand of replacement water filters for the frig for a couple years now.  They work really well.  They recommend that you replace the filter every 6 months, but these work really well and I think we've gone as long as 10 months (maybe longer) before noticing a difference in the water quality.  Definitely compare prices with the multi-packs because some sellers will sell one filter for the price you can find elsewhere for two or more!