Waterdrop filters are an excellent water filter and a very good price. My only reason for 3 stars and not 5 stars is their poor customer service. They do not answer the phone and their web site is very confusing when you are trying to compare filters. There should be a box you can check for each filter so you can compare them and they should put the model number with the description so you can see which one you are looking at. There is a model number that you can see when you are looking at the filter but it conveniently disappears when it shows you more suggested filters so you don't know what filter they are talking about. What the hell happened? Customer service did finally call me back after several days or maybe a week later but by then I was about to buy from another company and I was researching other filters. The other thing I do not like is when I tried to order a filter for my refrigerator I picked one filter but it would not let me buy just one although it showed they were in stock. I had to purchase 3 filters and it was not from Waterdrop it sent me to the Amazon website. It was a Waterdrop filter but Amazon sold it to me. I have purchased from Amazon before and I do not like them, they have very sneaky tactics to lure you into their environment. It took a few weeks and several emails to get disconnected from Amazon in the past and I actually had to cancel the credit card used so I would not get continuing monthly charges from them. I do not like Amazon and I just would prefer not to do business with them. What has happened to Waterdrop? Someone bought them because they email me under a different name. They still make an excellent filter.