The electric powered attic vent (1320 cfm) uses a thermostat to fight heat inside the attic. The thermostat adjusts from 60 to 120 degrees. It ventilates an area up to 1900 square feet and needs 562 square inches of net free intake air. The low pofile dome is unobtrusive when installed on the roof with the face slanting away from the front of the house. Other features: 25" diameter metal dome, 4 amp motor, 4 bladed fan blade, 14-1/2" diameter opening. Color is gray. There is a 5 year limited parts warranty and a 2 year limited labor warranty.