Pad Refills (Pack of 6 Pads) - 21 1/2" x 23 1/4" x 3/4" Quantity:Default the more efficient a filter

the more efficient a filter is at removing particles

Can be ordered in packages of 2 each only

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

these can be purchased in any conceivable size

28X Increased Efficiency

Pad Refills (Pack of 6 Pads) - 21 1/2" x 23 1/4" x 3/4" Quantity:Default the more efficient a filterPACK 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.