Gardeners who want to reduce unpleasant odors in their indoor garden can attach a Mountain Air Carbon Filter to their exhaust fan to remove 99% of odor-causing organic particles in one pass. This 12” filter is effective to 1200 cfm and maintains its odor-stopping power for 36 months. Unit measures 16” in diameter, 40” long, and weighs 75 lbs. Includes 12” flange.