20x20x4 (3 5/8) Furnace Air Filters MERV 12 Pleated Plus Carbon 2 Pack king shredder Lotus Pro Series Grow is

Lotus Pro Series Grow is specially formulated to give your plants exactly what they need to produce lush

*A control unit and reservoir (sold separately) are required to use this expansion pack

The fans include an in-line multi-speed controller with power switch to set the fan’s speed to optimal noise and airflow levels for various environments

Thanks to its dual side-by-side design

20x20x4 (3 5/8) Furnace Air Filters MERV 12 Pleated Plus Carbon 2 Pack king shredder Lotus Pro Series Grow isImportant 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