Carbo-Air-50 FilterCarboAir 50 CarboAir 50 has been developed to filter VOCs (Volatile Organic Compounds) from smaller grow room environments. CarboAir 50 has a 50mm bed of virgin activated granular carbon. It is the best filter for normal use in smaller grow rooms. A 50mm bed of carbon is perfect for smaller grow rooms. It offers excellent filtration of air without compromising air flow. Handmade in Europe Comes with a machine washable pre filter 18 month guarantee