Pad and Frame Air Filter (1 Frame and 6 Pads) - 20" x 21 1/4" x 1" Quantity:Default In general

In general

the greater it's resistance to airflow

28X Increased Efficiency

Any Kind of Filter's Extended Surface Pleated Filters outperform ordinary furnace filters with medium efficiency and are designed for lower pressure drop

oxidation and deterioration

Pad and Frame Air Filter (1 Frame and 6 Pads) - 20" x 21 1/4" x 1" Quantity:Default In generalIncludes one Frame and PACK of 6 pads The Pad and Frame Air Filter involves a permanent frame and replaceable filtration pad inserts. The permanent frame is constructed of space age plastics that are resistant to corrosion, oxidation and deterioration. Filtering inserts are anti microbial and are more efficient in capturing particles, such as dust, ragweed, pollen, etc., from the air stream, than standard fiberglass filters purchased at retail