Phat Charcoal Fiber Odor FiltersPhat charcoal fiber odor filters feature a tightly woven 3 layer charcoal fiber technology that removes particulate matter as well as odor and gasses from the air. This super efficient, high capacity odor filter can be used with high CFM fans unlike traditional carbon filters. Perfect for scrubbing and supplemental odor control. Great back up filter for controlled, sealed rooms with high temperature triggered exhaust fans. Greenhouse charcoal fiber