Cool Attic CX4000AMWG Power Attic Roof Mount Ventilator with 5.1-Amp PSC Motor and Steel Flange, Weathered Grey Galvanized Steel Dome 5.1-Amp Heavy-duty PSC 115-Volt 60-Hz motor Galvanized steel dome weathered grey Attics up to 2,400 square feet Adjustable automatic thermostat Prolongs life of composition roof shingles with lower summer attic temperatures