Merv 11 Pleated Air Filter - 9" x 11 3/8" x 1" Quantity:12-pack The "Practical Pleat" media is

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

This is designed to fit into 1" Return Air Grilles

Filtering inserts are anti-microbial and are more efficient in capturing particles

Filtering inserts are shipped in an easily stored packet

Instead of face loading (particles captured on the outer surface of the filter)

Merv 11 Pleated Air Filter - 9" x 11 3/8" x 1" Quantity:12-pack The "Practical Pleat" media isAny 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.