16x20x4 (3 5/8) Furnace Air Filters MERV 8 Pleated Plus Carbon 6 Pack food-&-water-storage Norwegian kelp improves nutrient uptake

Norwegian kelp improves nutrient uptake and increases yields

Cover with opaque plastic or foil

Best used for seed germination and propagation

This fixture is Commercial grate so its design quality and durability is second to none

• Compatible with 4" to 12"round air ducts

16x20x4 (3 5/8) Furnace Air Filters MERV 8 Pleated Plus Carbon 6 Pack food-&-water-storage Norwegian kelp improves nutrient uptakeImportant 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