Product review (4 stars): Tom
The filter is great and at a great price compared to buying it from the company that installed the humidifier. The salesperson that sold us the Aprilaire Humidifier made promises that were not true. He said one filter would last for an entire heating system. So far in the past two years, I have to change the filter three times a season. Based on that, I would probably not buy another Aprilaire 400 Humidifier.