Keep Your Home Odor-Free While Improving Air Circulation With This Charcoal Duct-Free Filter Kit. Not Only Does It Maximize Performance Of Your Range Hood It Also Stops Microscopic Droplets Of Grease And Food Particles Generated During Cooking. The Filter Catches These Particles From Drifting To Other Surfaces Such As Cabinetry Or Countertops Which Can Oxidize And Create An Unwanted Film Or Bacteria Growth. For Peak Performance Change Your Charcoal Filter Every 6 Months.