Air Purifier 9″ replacement PCO (Photocatalytic Oxidation) Cell Review May 1, 2018 No Comments This fits your . Make sure this fits by entering your model number. 9″ PCO (Photocatalytic Oxidation) Cell. Compare to ActivTek and EcoQuest 9″ RCI Cell Compatible with: EcoQuest DuctwoRx Residential ActiveTek Induct 2000 Tags: Cooling & Air Quality, Heating, Home & Kitchen, Parts & Accessories