Pad Refills (Pack of 6 Pads) - 21 1/2" x 23 1/4" x 3/4" Quantity:Default these can be purchased in

these can be purchased in any conceivable size

the greater it's resistance to airflow

28X Increased Efficiency

They are easy to install with custom air filters made to the sizes that you specify

You never have to hassle with disposable filters that will end up in a landfill again

Pad Refills (Pack of 6 Pads) - 21 1/2" x 23 1/4" x 3/4" Quantity:Default these can be purchased inPACK of 6 pads for Pad and Frame Air Filters 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 outlets. Filtering inserts are shipped in an easily stored packet.