Merv 11 Pleated Air Filter - 21" x 23" x 1" Quantity:12-pack To find the size the

To find the size the old unit should have sizing information printed on it

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

They are easy to clean by simply backwashing every month with cold water so you don‰۪t need expensive cleaners

The "Practical Pleat" media is up to 28 times more effective at capturing particles than standard fiberglass panel filters

28X Increased Efficiency

Merv 11 Pleated Air Filter - 21" x 23" x 1" Quantity:12-pack To find the size theAny 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.