Lennox Healthy Climate X6673 is a high-efficiency, OEM, MERV 11 (formerly a MERV 10) furnace filter that removes up to 98% of 0.3 microns from your home’s air! These microns include, but are not limited to, dust mites, mold, pollen, dust, and bacteria. Using this filter will keep your family’s indoor air healthy and it is especially important to have a filter of this caliber for any family member who has allergies, asthma, or any other respiratory illness. Because this filter is so efficient at filtering out harmful particles, it is important that you keep up with the maintenance of the X6673. Lennox Healthy Climate suggests you change this filter every 6 – 9 months!