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

these can be purchased in any conceivable size

To find the size the old unit should have sizing information printed on it

Filtering inserts are anti-microbial and are more efficient in capturing particles

One way to overcome this problem is to increase the surface area of the filter media

Pad Refills (Pack of 6 Pads) - 21" x 23" x 1" 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.