I have a friend who works in Gree Electric Appliances. I also saw in his circle of friends that there is a Gree water purifier that can be used for three years without changing the filter element. The model is 5081. He uses it at home. As far as I know, the quality of this one is pretty good, there is nothing wrong with it, and the dual water outlets are quite user-friendly. The most important thing is that it is very convenient without frequent core replacement. I also read about the product and user reviews on JD.com, and I think it’s pretty good, so I plan to buy it.