Product review (2 stars): Penny wise, pound foolish.
Worked fine for a few days, then the "Filter Condition" needle dropped to zero. Flipping it top for bottom would bring it back to life for a few hours, then zero again. That's what I get for trying to save a few dollars...$12 for a week of service against $19 for about six weeks' or more from the Holmes brand item. Your mileage may vary (apparently it does for some folks) but as for me, this is a one-time purchase, and a lesson learned.