20x25x4 (3 5/8) Pleated MERV 7 Air Filters 2 Pack CO2 Two separate lighting control channels

Two separate lighting control channels allow users to control two different lighting systems with separate setpoints

Made to fit comfortably in your hand for on-the-go testing

inner diameter hose size

Ergonomically shaped

7 ounces of powder will make up to 65 gallons of product

20x25x4 (3 5/8) Pleated MERV 7 Air Filters 2 Pack CO2 Two separate lighting control channelsImportant 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 20x25x4 filter