Shutter Mount Exhaust Fan, Assembled Assembled, Blade Diameter 16 in, Blade Material Aluminum, Control Type Rotary Dial, Drive Type Direct Drive, Duct Diameter Not Applicable, Exhaust Airflow @ 0.000 in SP 1,850 cfm, For -Out Height 18 in, For -Out Width 18 in, For Maximum Wall Thickness 5 in, For Minimum Wall Thickness 5 in, Frame Material Aluminum, Guard Finish Chrome, Guard Material Steel, Guard Type Intake, Housing Material Aluminum, Housing Finish Aluminum, Includes Shutter