20x20x5 (4 3/8) Honeywell/Lennox Replacement MERV 15 Air Filters 4 Pack drying-racks Converts Digital Signal to Analog

Converts Digital Signal to Analog Signal

User-definable vacuum and sealing times

it features a resin cased circuit board with a sealed bearing fan so it will run cooler than any other ballast and it’s been tested to withstand the extreme atmospheric conditions of virtually any growing environment

This water pump is oil-free to prevent nutrient reservoir contamination

Air Purity and Fresh Air

20x20x5 (4 3/8) Honeywell/Lennox Replacement MERV 15 Air Filters 4 Pack drying-racks Converts Digital Signal to AnalogImportant 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. We also carry 4 7 8 and 5 1 4 inch depth filters,