16x20x4 (3 5/8) Furnace Air Filters MERV 10 Pleated Plus Carbon 2 Pack sprayers Tested: The efficacy of GrowSafe

Tested: The efficacy of GrowSafe has been studied extensively

Trims up to 30 lbs per hour dry and 90 lbs per hour wet

as well as for homeowners and hobby growers

For ongoing control or severe infestations

FCC listed

16x20x4 (3 5/8) Furnace Air Filters MERV 10 Pleated Plus Carbon 2 Pack sprayers Tested: The efficacy of GrowSafeImportant 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 16x20x4 filter