Field Controls 46600405 Flex-4 Filter Kit 16x25 & 20x25 Replacement 4" Filter 6/Case

The Field Controls 46600405 Flex Filter Flex-4 is an air purifier used in air cleaning units to remove airborne particles such as dust and debris before air enters the air handler or furnace in return air sections in HVAC systems. It has 16" x 25" and 20" x 25" filter housings, allowing flexible fitting across multiple return air cabinets. It is used in heating and cooling systems to maintain airflow conditions, protect internal components like coils and blowers, and support consistent system performance across ducted air distribution equipment.