Product review (5 stars): Highly recommend these filters
I bought a two pack of this exact same brand / model number from a different seller, and it's worked flawlessly.  I use them for exactly 6 months as recommended.  I just hit the 6 month mark on the first of the two pack, and just installed the second, and so far as I say they've worked exactly as designed, and produce good tasting water.  Not a drop of water has leaked through the tiny O-rings either, from what I've observed.  I'm about to buy this 3 pack to replenish my now empty inventory, since this amazon seller is offering them at such a good price.