Product review (1 stars): Just a bad one, I don't know...
I bought the 2 pack for my LG several months ago and just got around to installing one.  Following the instructions, I lubed the O rings and seated it in place.  I ran about 32 oz. of water and all of a sudden I heard a pop.  I opened the refrigerator door and water was running out all over the place.  I re-seated the filter and tried again but water was flowing everywhere.  I put the old LG filter back in, everything works fine.  I checked the O rings on the Water sentinel and they look fine so I tried 2 more times but each time it continued to leak (not just a drip but a lot of water).  After looking at the filter to see if both the LG and the WS looked the same I saw that the holes between the O rings on the WS are much smaller and in a different position than on the LG.  I have no idea if this makes a difference but, there is certainly something wrong.  Our water pressure, the last time I checked was at 55, well within the 30-100 they recommend, so I don't think that is the problem.  I am hesitant to try the other WS filter that I have, I may just toss it because even if it does work initially I don't trust it and don't want my refrigerator full of water.  I certainly didn't save any money by not buying the OEM version.