Accumulair Gold 17.25x26x4 (Actual Size) MERV 8 Air Filter/Furnace Filters (4 pack) Actual Size of Filter: 17.25 x 26 x 3.75 MERV 8 Rating. Each filter lasts up to 3 months. Traps most large allergens including pollen and lint. Electrostatic charge captures airborne allergens SMALLER THAN 1 micron including fine dust, smoke, dander, mold, pet dander and dust mites. Also traps most large allergens including pollen and lint. 4 Pack of Air Filters