They do it with a series of specially shaped vanes that catch the wind and provide rotary motion.TURBINE 12"" MILL INTRNL Turbine vents provide a low-cost ventilation alternative in areas where wind speeds of at least 5 mph are typical.. This pulls hot humid air from the attic.
Smaller design for sleek smooth finish.If you are the smoker type you can appreciate these GTS window guard now you can keep the window open while it rains. No tape or hardware to install.