Filtrete 12"x20"x1" Gray Basic Dust & Lint Pleated Furnace Air Filter with MPR 300. Electrostatically charged to attract and capture large airborne allergens like pollen, household dust, and lint, it performs better than ordinary fiberglass and washable 1" filters. Ideal for high velocity heating/cooling systems, this filter lasts up to 3 months. For residential use only.