20x20x4 (3 5/8) Pleated Air Filters MERV 13 Plus Carbon 1 Pack harvest-solution - Includes Vitamin B1 to

- Includes Vitamin B1 to ease shock and stress on plants

We have raised the bar in this industry for your safety

Twister Rails allow two Twisters to be placed back-to-back on an adjustable incline

Case of 100

20x20x4 (3 5/8) Pleated Air Filters MERV 13 Plus Carbon 1 Pack harvest-solution - Includes Vitamin B1 toImportant 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