Filtrete MPR 1000 20 x 25 x 4 Micro Allergen Furnace Air Filter, 4-Pack – $40 @ Amazon Free Shipping By admin | June 6, 2018 9:57 am EST 0 Comment Comes to $10/filter for this 4 pack of 20*25*4 (same price as the 2 pack).https://www.amazon.com/gp/product…UTF8&psc=1