14x18x1 (Actual Size) Accumulair Emerald 1-Inch Filter (MERV 6) (6 Pack) * MERV 6 Rating * Each filter lasts up to 3 months. * Supercharged pleated panel filtering media ideally suited for capturing fine airborne allergens such * Buy over a year of filters in one purchase ( Each filter lasts 3 months under normal use)