Practical Pleated Air Filter (2-Pack) - 24 1/8" x 36 1/8" 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

Available in packs of 4

the more efficient a filter is at removing particles

This is a 5" MERV 10 HIGH PERFORMANCE AIR FILTER

Practical Pleated Air Filter (2-Pack) - 24 1/8" x 36 1/8" 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