Pad Refills (Pack of 6 Pads) - 18" x 20" x 1" Quantity:Default some just refer to them

some just refer to them as electrostatic filters

the greater it's resistance to airflow

if not you can measure it or check the HVAC unit and the owner‰۪s manual

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

The "Practical Pleat" contains over 500% greater surface area than a MERV 10 one-inch pleat

Pad Refills (Pack of 6 Pads) - 18" x 20" x 1" Quantity:Default some just refer to themPACK 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.