Merv 8 Pleated Air Filter - 6" x 13 1/2" x 1" Quantity:12-pack and the greater the pressure

and the greater the pressure drop it creates

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

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

Unlike some permanent custom air filters

In general

Merv 8 Pleated Air Filter - 6" x 13 1/2" x 1" Quantity:12-pack and the greater the pressureAny 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.