A turtle roof vent resembles a turtle's shell and has no moving parts. Hot air and moisture exit through these vents because of natural convection currents.
Cool air enters the attic through soffits, heats up and escapes through turtle vents. Because of this air movement, turtle vents work best when placed close to a roof's ridge. Individually, these vents are not very effective, so a roof typically requires several for adequate ventilation. Proper air flow is necessary to reduce heat in the summer and limit moisture accumulation and ice dams during winter. Turtle vents are also known as louvers or low profile, flat or box vents. They are available in both metal and plastic.