RV28ML Roof Mounted Power Attic Ventilator, Gray, 25" Diameter Metal Dome, 1,320 CFM, Ventilates Up To 1,900 SQFT, WithAdjustable Thermostat From 60 To 120 Degrees, 4A Motor, 4 Bladed Fan Blade, 14-1/2" Diameter Opening, Needs 562 SQIN Net Free Intake Area, 5 Year Limited Parts Warranty, 2 Year Limited Labor Warranty.