Merv 13 Pleated Air Filter - 21" x 23" x 1" Quantity:12-pack some just refer to them

some just refer to them as electrostatic filters

You never have to hassle with disposable filters that will end up in a landfill again

Includes one Frame and PACK of 6 pads

Unlike some permanent custom air filters

The "Practical Pleat" contains over 500% greater surface area than a MERV 10 one-inch pleat

Merv 13 Pleated Air Filter - 21" x 23" x 1" Quantity:12-pack some just refer to themAny 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.