Roof louvers are a type of attic exhaust vent that make up half of a balanced attic ventilation system for each roof. Intake vents make up the other half of the system. Together they help remove any built-up heat and moisture inside the attic for year-round ventilation. Use the Lowe's calculator to determine how many individual roof louvers are needed per roof. Large size means fewer vents needed 144 Square inches of Net Free Area airflow each Galvanized steel construction Round dome design with 14-in opening Suitable for 3/12 to 8/12 roof pitch Part of a balanced attic ventilation system for year-round airflow Helps to fight heat and moisture buildup inside an attic as well as ice dams in cold climates Requires intake ventilation for proper performance Use the Lowe's online calculator to determine how many are needed for each attic Color/Finish Family: Black Manufacturer Color/Finish: Black Series Name: N/A Type: Round Height (Inches): 8.625 Length (Inches): 25.625 Rough Opening Length (Inches): 14 Rough Opening Width (Inches): 14 Weight (lbs.): 9.3 Width (Inches): 25.375 Damper Included: No Material: Galvanized steel Net Free Area (Sq. Inches): 144 Rain Diverter Included: Yes Screen Included: No Warranty: 5-year limited CA Residents: Prop 65 Warning(s): Yes UNSPSC: 30151600