This cell is for the following models of Fresh Air Purifiers: 

• Fresh Air 2
• Fresh Air 2.1
• Fresh Air 2.2
• Fresh Air 3.0
• Fresh Air Black
• FreshAir Surround
• FreshAir Everest

RCI ActiveOx Cell is an essential part of Fresh Air purifier to eliminate smoke, odors, and reduce airborne contaminants. 
  
The RCI Cell should be replaced when UV Light Bulb is burned, or every year, whichever comes first.