ASRHPML Roof Mounted Power Attic Ventilator, Gray, 25" Diameter Metal Dome, 1,500 CFM, Ventilates Up To 2100 SQFT, With Adjustable Thermostat From 60 To 120 Degrees & Adjustable Humidistat From 20% To 90%, Thermostat Runs Fan In Summer, Humidistat Runs Fan In Winter, 4.3A Motor, 6 Bladed Fan Blade, 14-1/2" Diameter Opening, Needs 720 SQIN Of Net Free Intake Area, 10 Year Limited Parts Warranty, 5 Year Limited Labor Warranty.