Merv 8 Pleated Air Filter - 8 7/8" x 34 5/8" x 1" Quantity:12-pack You may know them as

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

Unlike some permanent custom air filters

Simply cut a hole

This is designed to fit into 1" Return Air Grilles

Merv 8 Pleated Air Filter - 8 7/8" x 34 5/8" x 1" Quantity:12-pack You may know them asAny Kind of Filter's Extended Surface Pleated Filters outperform ordinary furnace filters with medium efficiency and are designed for lower pressure drop, and long service life which reduces HVAC equipment maintenance and energy costs. A higher MERV rating means that the air filter that you are about to purchase possesses a higher amount impurity filtration ability than your ordinary filter.