20x20x4 (3 5/8) Pleated MERV 15 Air Filters 1 Pack Growing Accessories Has 2″ face and is

Has 2″ face and is made of polypropylene

It can measure up to 5000ml liquids

Use during your flush to help break down salts

Digesting the biomass of the pathogen

The granules expand when hydrated

20x20x4 (3 5/8) Pleated MERV 15 Air Filters 1 Pack Growing Accessories Has 2″ face and isImportant 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