Practical Pleated Air Filter (2-Pack) - 20" x 30" x 5" Quantity:Default the greater it's resistance to

the greater it's resistance to airflow

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

Includes one Frame and PACK of 6 pads

the A+2000 uses stage loading

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

Practical Pleated Air Filter (2-Pack) - 20" x 30" x 5" Quantity:Default the greater it's resistance toYes, 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