Practical Pleated Air Filter (2-Pack) - 19 1/2" x 24 1/2" x 5" Quantity:Default And there are no metal

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

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

the A+2000 uses stage loading

Eliminates Filter Bypass

The permanent frame is constructed of space-age plastics that are resistant to corrosion

Practical Pleated Air Filter (2-Pack) - 19 1/2" x 24 1/2" x 5" Quantity:Default And there are no metalYes, 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