AO Smith Reverse Osmosis Membrane Replacement for AO-US-RO-MB-4000, 1 Count

Works for what it is intended to.

There's mixed reviews as to whether this filter fits the pure Blue H2O system from Costco . It fit mine with minimal modification as others suggested. Just remove the triangle tab on top of the filter. I bought new filters for the system thinking they were the cause of the slow flow rate of water, in the process I discovered that my water tank was low on pressure and had to simply add air to the system through the valve stem. It fills up just like a bicycle tire. Worth checking while you're working on the system, you can find many YouTube videos on it. My system was due for new filters anyway and this was my only option left for the R. O. filter. Glad it worked! Hope this helps others as well.

Easy to install, no leakage, good water flow, good quality, no smell

Not as good as the original DuPont membrane but does the job. TDS around 15-20 as compared to 8-12 with the original.

We love the fresh clean water from this filter