Replacement for Filtrete, Nordic Pure - Filtertree High Efficiency air AC filters / Furnace filters, MERV 4, 20x30x1 inches, 5 Pack (20 X 30) Capture large airborne allergens like: Pollen, Household Dust, Lint Improve your home's air quality by upgrading your MERV rating Each filter lasts three months Measures 20 inches by 30 inches by 1 inch Comes in a pack of five(5) filters