Pad Refills (Pack of 6 Pads) - 23 3/4" x 23 3/4" x 1" Quantity:Default And there are no metal

And there are no metal parts that could lead to corrosion or oxidation within the filter

Instead of face loading (particles captured on the outer surface of the filter)

Eliminates Filter Bypass

This is designed to fit into 1" Return Air Grilles

Pad Refills (Pack of 6 Pads) - 23 3/4" x 23 3/4" x 1" Quantity:Default And there are no metalPACK 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.