LL Building S30 Masterflow 30 Inch Whole House Automatic Fan Ceiling Shutters

Key Features

• Injection molded frame with smooth aluminum louvers that automatically open when fan turns on, and close when fan turns off to keep out air, insects, and dust
• Balanced shutters for complete automatic service-free operation

Whole house fan ceiling shutters automatic - no-cut joist"seal-tite" white enamel finish Injection molded frame with smooth aluminum louvers that automatically open when fan turns on, and close when fan turns off to keep out air, insects, and dust. Balanced shutters for complete automatic service-free operation. Installs centered on joist with 18 inch or 24 inch centers with 2 cut openings, 1 on each side of center joist per shutter model. 35-3/4 inches length by 30-1/4 inches wide outside dimensions, 33-3/4 inch length by 28-1/4 inch wide opening.