This Range Hood Recirculation Kit Can Be Used In The Kitchen When Venting To The Outside Is Either Not Possible Or Not Desirable. The Kit Includes A Charcoal Filter That Freshens Air As It Recirculates Back Into The Home. This Is An Accessory That Can Be Used Across Several 30" Range Hood Models Including Uxt40, Uxt42 And Uxt52; Check To See If Your Model Number Is Compatible. Kit Includes (1) Charcoal Filter, (1) Black Vent Cover And (4) Mounting Brackets. Replacing This Accessory Will Require Basic Hand Tools, Some Disassembly Of The Appliance And Novice Repair Experience. You Must Unplug The Appliance Or Shut Off The House Circuit Breaker Before Installing This Accessory. Helpful Tip: For Optimum Performance Of Your Vent, Change The Filter Every 6 Months Or When A Loss Of Airflow Can Be Detected.