Reverse Osmosis Membrane Replacement for the AO-US-RO-MB-4000 - Not Compatible with SmartFlow Systems

It worked beautifully when it was first installed several years ago. It was replaced recently and continues to do the job of filtering drinking water.

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

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.

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

Very easy install. Unscrew the housing remove the membrane and screw on new membrane.

Works for what it is intended to.

While the filter itself fit our RO unit, the connection to the red RO tubing required a different type of connection (from an elbow fitting to a direct line into the filter), but the instructions that came with the filter did not mention this difference or how to release the tube that had been fitted into the replacement filter to keep it fresh during transit. Instead of being able to change the membrane ourselves, as we had always done in the past, we had to call a plumber, who also wrestled with the device, at significant cost to us. And then, they broke the faucet in the process of installing the membrane, which meant we had to buy a standalone RO faucet, and then have a plumber install that one as well, which never worked (the tank never filled and the sink sounded like Niagara Falls for a week as water apparently cycled from the faucet directly into the drain). Plumbers couldn't figure this one out, so we got a an entirely new system installed (inexpensively, thanks to our amazing home warranty), and we won't use any AO Scott Products in the future. You could call it a perfect storm or a series of misfortunate events, but if we'd only received the correct instructions in the replacement filter, I'm sure I'd be giving this item five stars, so do with that what you will.

This filter came in original AO Smith packaging and was not damaged!