FEATURES A 120V SINGLE-PHASE PERMANENTLY-LUBRICATED MOTOR WITH THREE ALUMINUM FAN BLADES THAT MOVE FROM 950 TO 1500 CFM OF AIR AT JUST 59DB MAKING IT IDEAL FOR COMMERCIAL KITCHENS & INDUSTRIAL SETTINGS. ADJUSTABLE SHUTTERS HELP PREVENT BACK DRAFTS WHEN THE FAN IS NOT IN USE REGULATE AIRFLOW AND PROVIDE PROTECTION FROM RAIN & SNOW. THE FAN IS INSTALLED ON INSIDE WALL WITHOUT THE NEED FOR EXTERNAL FRAMING. OSHA & UL507-COMPLIANT UL & CUL LISTED.