The gable mount power vent (1620 cfm) uses a thermostat to prevent heat build up and a humidistat to prevent moisture build up inside the attic. The thermostat adjusts from 60 to 120 degrees and runs fan in summer. The humidistat adjusts from 20% to 90% and runs fan in winter. It ventilates an area up to 2300 square feet and needs 778 square inches of net free intake air. Other features: 15" diameter housing, 14" diameter fan blade, 3.7 amp motor, 4 bladed fan blade. Use shutter model number 54703 with this vent. There is a 10 year limited parts warranty and a 5 year limited labor warranty.