3M Filtrete Micro-Allergen Reduction Furnace Filter - 16-in x 20-in x 1-in. This Filtrete furnace air filter by 3M will effectively trap microparticles thanks to its electrostatic capabilities. In doing so, it will ensure that the air in your home remains clean and free of pet dander, smoke, and household dust. The filter also takes care of larger particles such as pollen, lint, and mould spores. It measures 16 inches by 20 inches by 1 inch and delivers up to 3 months of filtering performance. It's best to replace it seasonally to ensure that the airflow of your home remains optimal and pure. This product outperforms other 3-month, 1-inch filters as well as fibreglass, washable, and non-electrostatic pleated filters.