20x20x4 (3 5/8) Furnace Air Filters MERV 12 Pleated Plus Carbon 2 Pack Lighting Accessories Elite CalMag ensures that the

Elite CalMag ensures that the most common nutrient deficiencies are handled with one treatment

including Temperature

and flowers sticky like oil pesticides can

full-size dimensions and volume to provide maximum growing area

20x20x4 (3 5/8) Furnace Air Filters MERV 12 Pleated Plus Carbon 2 Pack Lighting Accessories Elite CalMag ensures that theImportant Note: Almost ALL furnace filters have a different "actual size" than the nominal size printed on the air conditioner filter. It's best if you measure your air filter for the EXACT size and compare it to our "Actual Size" and then you can be sure your A C air filter fits! With the 4" and 5" air filters there is a wider variance between the nominal and actual size depending on the manufacturer. If you are replacing a 4 3 8 depth 20x20x4 filter