The BROAN QT20000 range hood combines modern styling and quiet operation to make cooking more relaxing and social. The patented air chamber reduces noise up to 40% over conventional hoods. The infinitely adjustable rotary speed control on this hood lets you choose your optimal setting. The larger filter area captures steam and odor for a more enjoyable kitchen experience, especially when you're serving a crowd. Ducted or non-ducted recirculation capability makes installation easy in most any applications. 3-1/4 in x 10 in adapter/damper and 7 in round adapter included, optional 7 in round damper (BP87) to prevent backdrafts sold separately. For non-duct recirculation replaceable charcoal filter is available that simply clips on to the back of the grease filter, sold separately.