Provides maximum ventilation even when it rains. The three speed fan allows selection of intake or exhaust operation. The powerful 4 amp motor and 12" diameter, 10-blade fan easily removes musty air, smoke and cooking odors while preventing heat build-up. Provides over 900 CFM on high speed, 680 on medium and 500 on low. The Model 1200T with thermostat allows the fan to cycle on and off when you're gone. Simply adjust the thermostat to your desired temperature and the 1200T will do the rest, RAIN OR SHINE! Attaches directly to your existing 14" x 14" standard roof vent with no vent removal required. Both models feature a translucent white, high density polyethylene rain cover with UV inhibitors. Overall size: 32-1/2" x 20-1/2" x 9-15/16".