Product review (4 stars): Metal hurts like a mf
These seem to do what they're supposed to. They start to turn brown as they age which is to be expected. We don't dry ours out as regularly as we should so we replace them every month. I docked a star because the metal piece that goes throughout the filter hurts like a MF when you're trying to smash it into the humidifier. Be careful because I've cut myself on this thing.