Broan economy 40000 series 36-inch under cabinet mount range hoods feature a two-speed fan, a rocker-type fan and light control, and a polymeric blade and light lens. These range hoods are 160 cfm and have a 6.5 sone rating, for quiet operation. With this kitchen range hood, you have the option of ducting vertically or horizontally. The mitered sides and hemmed bottom ensure safety and clearance of the cabinet door. Keyhole mounting slots make the range hood easier to install. Four-way convertible; installs ducted 3-1/4-inch-by-10-inch (vertical and horizontal), 7-inch round (vertical) and non-ducted.