Practical Pleated Air Filter (2-Pack) - 6" x 6 1/8" x 5" Quantity:Default You may know them as

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

PACK of 6 pads for Pad and Frame Air Filters

The Pad and Frame Air Filter involves a permanent frame and replaceable filtration pad inserts

the more efficient a filter is at removing particles

Practical Pleated Air Filter (2-Pack) - 6" x 6 1/8" x 5" Quantity:Default You may know them asYes, we even have the odd sizes! The "Practical Pleat" media is up to 28 times more effective at capturing particles than standard fiberglass panel filters. In general, the more efficient a filter is at removing particles, the greater it's resistance to airflow, and the greater the pressure drop it creates. One way to overcome this problem is to increase the surface area of the filter media. The "Practical Pleat" contains over 500% greater surface