19.875x21.5x1 MERV 13 - 6 Count - Pleated HVAC, Furnace & Air Conditioner Filters - For Bacteria, Dust, Cold & Flu Germs, Lint, Mold, Pet Dander, Allergy-Causing Pollen, Smog, Smoke & Viruses

Designed to filter microscopic particles such as lint, dust mites, spores, pollen, pet dander, fine dust, smoke, viruses, and bacteria Simple to install and a cost-effective step towards a healthier home environment. For best results, change your filters every 60 to 90 days but increase frequency to 30 days during peak summer and winter months 100% synthetic electrostatic media for high efficiency with low air flow resistance