Activated carbon filter with diameter 150 mm and optimal flow rate of 475 mc / h, maximum flow rate 620 mc / h. Very useful for reducing odors * present in the air extracted from the extractor. Activated carbons are to be replaced when you start to perceive odor. The average duration is 15 months. They can cause pressure drops in the suction system up to 30%.    * Felling is ensured if the greenhouse is hermetically close - See more at: https://www.indoorline.com/filtri-ai-carboni-attivi-k2602-max-620-opt-475mc-h-flangia-150mm-