Mountain Air Activated Carbon Filters remove 99% of everything under 20 microns, from the air in one pass. This includes all organic odors. Some of the uses of these superior air cleaners are: food processing, indoor growing, restaurants, mortuaries, or anywhere odors and air quality are an issue.MountainAir carbon is derived from an allocthonous, subbituminous black coal, deposited in the Devonian Period in a Pre- Cambrian formation, within the Collie Basin, over 230 million years ago. It is the planet’s oldest coal. It has extremely low ash content. Trace element discrimination demonstrates it to be physically and chemically unique.Features-Highest quality filter on the market-Lasts Longer-Eliminates odours completely-Maximum airflow providing 100% odour control-Airflow figures, indicative of 37 month intensive flowering room filter testing programme, after which filters were still found to be 100% effective-Filters can use much higher air flows, but these figures are for efficient and economical use-Supplied with 2 filter sleeves, hand & machine washableMountain Air Carbon:Mountainair carbon is over 280 millions years old and is found in west AustraliaMountain air do NOT use RC 412 as used by budget filters, which is simply amalgamated black coalMountain air carbon is used where quality filtration is needed, also used in gas masksHints & Tips:Filters used best below 80% RH, Over 85% RH they don’t workFilters work best below 32°C (89°F), Daytime growing area should idealy be between 21°C & 27°C (70-81°F)Best to suspend filter from ceiling, using chains and hooks, for safety and reliabilityGrower’s Tip:To determine the proper filter/ fan size for your indoor garden you must first calculate the size of your room (length x width x height) and divide that number by how quickly you would like the air in the room to be exchanged (we suggest 1-3 minutes). This number is the recommended MINIMUM CFM that is needed for the room.