This 8" Round Range Hood Air Kit, Works With Hoods That Have Ventilation Greater Than 400 Cfm. This Kit Improves Indoor Air Quality And Range Hood Performance By Replacing The Air Removed From A Room During Ventilation. This Is An Accessory Item That Can Be Used Across Several Brands; Check To See If Your Model Number Is Compatible. Installing This Accessory Will Require Basic Hand Tools, Some Disassembly Of The Range Hood And Novice Repair Experience.