Product review (4 stars): Works great, saves cleaning
Have use these for a couple years. They work very well and last about 6 weeks in my 2- 0.8 gallon humidifiers, so long as I use them regularly. I've found that if I don't need the humidifier I still need to run it for a few minutes every day to make sure the bacteriostatic silver gets distributed onto the filter. It's less effective for mold, but still good if you are running the machine continuously.