20x20x4 (3 5/8) Pleated Air Filters MERV 15 Plus Carbon 6 Pack New-releases 2 flotation disks

2 flotation disks

and fungus gnats

Along with lowering pH levels

Unlike other brands

CO2 (PPM) sensor and photocell to create the perfect all-in-one environmental sensor

20x20x4 (3 5/8) Pleated Air Filters MERV 15 Plus Carbon 6 Pack New-releases 2 flotation disksImportant 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