Best Internal Blowers Provide Exceptional Performance And Sound Levels That Are Both Quiet And Gratifying. (Ul)(Li)850(V) @ 10.5 Sones / 950 Max Cfm @ 10 Sones (High)(/Li)(Li)Duct Size: 3-1/4" X 14"; Recommended Transition 459(/Li)(Li)Blower Can Be Used In Vertical Or Horizontal Orientation. (Internal Blowers Are Located Inside The Range Hood.)(/Li)(Li)For Use With Up26M, Pik(/Li)(Li)Thermal Overload Protected(/Li)(/Ul)