The Cannabis Odor Reducing Advanced Carbon Air Vent Filters will remove levels of concentration of gases (VOCs) as well as larger particulates in the air. The activated carbon filter media is very porous and works by adsorption of the odor-causing compounds as air passes through the media. Meaning they get trapped in the pores and once all the pores are full, then the carbon stops capturing the gases and odors. Use in bathrooms, bedrooms, kitchen, family room, and RV/Motor Homes. When air flows through the filter, dirt, dust, smoke, and pollen-sized particles are trapped. The filtered air then passes back into your house. Easy Installation. Remove the register vent. If needed, cut the vent filter with household scissors using your register vent as a guide. Most vents will be 2 1/4" X 12" - 4" X 10" - 4" X 6" - 4" X 12". Install in the bottom of the air register or in the register opening. To prevent airflow restriction and for maximum filtration inspect the filter regularly and replace it when dirty, approximately every 60- 90 days. Note: Do not use in every vent in your home. This could cause airflow restriction and damage your furnace/AC unit. This product is not intended to replace your AC/Furnace filters. Air vent filters must be used in addition to your required Air Conditioner/Furnace filter for your HVAC unit. Air vent filters will increase your indoor air quality when used with your Nordic Pure HVAC air filters!