Power Cool Roof Mounted Attic Fans •   Automatic thermostat fights heat buildup. •   "Plus" an automatic humidistat to fight moisture buildup. •   Oversized 24" x 24" G-90 galvanized base for easy nailing and flashing. •   22-gauge cold rolled steel dome is more durable than aluminum; powder     -coated for extra protection against weather elements.     Screws are painted to match dome color. •   Six-blade design, versus five blades of some other brands,     and balanced motor for maximum CFM performance and motor efficiency. •   Six brace struts firmly hold dome in place. •   Raised dome for greater airflow and easier flashing. •   Plastic screen has three distinct advantages over metal: it won't corrode     or rust, it won't vibrate or create noise, and it's more pliable     and easier to hold firmly in place. •   Thermal overload protection -- an important safety feature     that shuts off motor if fan overheats. •   Ten-year limited warranty