Features: Two velocity legislation Controller for Inline Tent Extractor Fan Duct Night vision button with Steel body It is terribly Safe and handy to apply it With the steel wall leadership switch soft evening imaginative and prescient It is for the supporting pipe of a blower fan The cfm of the fan is 198 m⊃3;/h, the sound is 26dB once you set the controller to &;high&; The cfm of the fan is a hundred sixty five m⊃3;/h , the sound is 23dB once you set the controller to &;low&;. Package Include: 1*Dual Speed Switch