Nordic Pure 12x24x1M4Poly-6 Quantity 6 MERV 4 Poly TA Disposable Air Filter Actual Size of Filter: 11 3/4 x 23 3/4 x 3/4 Maintain excellent air flow-great for units with restricted airflow Great inexpensive replacement air filter ASHRAE rating of MERV 4 Nordic Pure Manufacturer Direct since 1960-Made in the USA