This Range Hood Recirculation Kit can be used when venting to the outside is either not possible or not desirable. This recirculation kit with charcoal filters can be used to freshen air and recirculate it back into the kitchen. This complete kit is an accessory that can be used across several brands; check to see if your model number is compatible. Kit includes (4) charcoal filters, (1) silver vent cover and necessary installation hardware.Installing this accessory will require basic hand tools and novice repair experience. Remember to turn off the appropriate 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.