Pad Refills (Pack of 6 Pads) - 21 1/2" x 23 1/2" x 1" Quantity:Default and the greater the pressure

and the greater the pressure drop it creates

This is designed to fit into 1" Return Air Grilles

You may know them as washable air or even permanent air filters

high quality Air Filters to you

Some of the other benefits of A+2000 custom air filters include the following

Pad Refills (Pack of 6 Pads) - 21 1/2" x 23 1/2" x 1" Quantity:Default and the greater the pressurePACK 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.