... 2.Carbon layer thickness: 35mm,50mm Activated Carbon Filter for Inline Duct Booster Fan *Carbon layer thickness: 35mm, 50mm* ... Color available: Black, Grey 1. Working principle Activated carbon filters behave as sponges and trap most airborne gases and odors ... technical parameter We can supply you all the Greenhouse systems: Inline ventilation fan, Grow tent, Carbon filter, Light reflector, Electronic ...