16x20x4 (3 5/8) Furnace Air Filters MERV 12 Pleated Plus Carbon 2 Pack Water Treatment Patent-Pending dual impeller design pumps

Patent-Pending dual impeller design pumps water on one end and generates oxygen on the other

optimized root growth

Fish-Mix boosts growth of all living organisms in the substrate as well as improving and stimulating production of microorganisms and useful bacteria in every type of soil and coco-based substrates

The Safer Brand Insect Killing Soap utilizes the power of potassium salts of fatty acids (insecticidal soap)

●【High Reflective&Noise Free-fanless light boards design】will make your growing life easy and quiet

16x20x4 (3 5/8) Furnace Air Filters MERV 12 Pleated Plus Carbon 2 Pack Water Treatment Patent-Pending dual impeller design pumpsImportant 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