merv 13 4inch 90-A-04PK-SO_thickness_10 These efficient air filter cartridges

These efficient air filter cartridges capture airborne particles as small as 1

Pleated carbon postfilter for HEPA air cleaner

1 VOC carbon canister and Replacement O-ring/gasket

purchase Aprilaire 213 or Aprilaire 413

The bottom is labeled "bottom"

merv 13 4inch 90-A-04PK-SO_thickness_10 These efficient air filter cartridgesThis filter was specifically designed for an easy retrofit into a typical 4" furnace filter track to increase efficiency High Efficiency cleaner air to breath Heavy duty, 100% reclaimed fiber, beverage board frame with expanded metal backing providing exceptional strength High Capacity model: more pleats = longer service life This product is an upgrade from a typical MERV 8 or MERV 11 furnace filter Price per filter, 6 Filters per case Advantages High