20x20x4 (3 5/8) Pleated Air Filters MERV 14 Plus Carbon 1 Pack Odor Control HM-500 Replacement pH probe

HM-500 Replacement pH probe

renewable junction

the potential for product contamination

each with its own fan port designated for each of the zones

Nitrogen (N): 3

20x20x4 (3 5/8) Pleated Air Filters MERV 14 Plus Carbon 1 Pack Odor Control HM-500 Replacement pH probeImportant 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