Product review (4 stars): Great Replacement Filter
This filter is just as good as the original. I have been using one of these filters for over 4 months now and there is no evidence of deterioration or mold whatsoever. I will offer two helpful hints to potential consumers: (1) Make sure you use an antibacterial additive in your humidifier every time you refill your reservoirs and (2) Always rotate your filter upside down each time you add water. This will GREATLY increase the lifetime of your filter. Also, the twin pack is a great buy!