The Broan 40000 21 In. Series Is Made For A Wide Range Installations And Comes In A Variety Of Appliance Matching Colors And Widths. The Durable Under Cabinet Hood Installs As 3-1/4 In. X 10 In. Ducted Opening Only And Ducts Either Vertically Or Horizontally. The Hood Features A Fan Designed For Years Of Trouble Free Service, An Easy To Clean Grease Filter, A Protective Lamp Lens That Distributes Light Evenly Over The Cook-Top And Control Switches For Fan Speed And Light Activation. Includes Duct Adapter With Built-In Damper.