16x20x4 (3 5/8) Pleated Air Filters MERV 13 Plus Carbon 1 Pack spl_dlw SNS-604A and SNS 604B are

SNS-604A and SNS 604B are each one-part nutrient additives to be used throughout the plants growing and flowering cycle

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

the Pro Hammerhead DE is made from highly reflective hammertone aluminum and is compatible with with double-ended lamps up to 1000W

Nordic Pure 16x20x2 MERV 8 Plus Carbon air filters are made of a dual material where the MERV rated material has been fused together with a carbon layer

16x20x4 (3 5/8) Pleated Air Filters MERV 13 Plus Carbon 1 Pack spl_dlw SNS-604A and SNS 604B areImportant 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