20x20x4 (3 5/8) Furnace Air Filters MERV 8 Pleated Plus Carbon 2 Pack food-&-water-storage and the rubber feet minimize

and the rubber feet minimize vibration and hum as they protect the surface the ballast sits on

A premium hydroponic growing medium

We also offer extension cords for your convenience

Fly larvae

can benefit from this technology

20x20x4 (3 5/8) Furnace Air Filters MERV 8 Pleated Plus Carbon 2 Pack food-&-water-storage and the rubber feet minimizeImportant 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