GrowBright 4″ Duct Filter
Improve air quality in the grow area with GrowBright duct filters, a simple dust and small particulate filtration elastic cover for air intakes.
Features:
•  Dust & small particulate filter for 4″ round duct/flange air intakes
•  Low restriction dual-layer design
•  Outer bug/larger-particle screen layer
•  Inner activated-carbon-lined smaller-particulate layer
•  Fits over standard 4″ round ducting/duct flanging