The Aura Gravity Retrofit Ventilator is an ideal alternative for an outdated roof turbine. The Aura Gravity Vent operates on the principle of the Venturi Effect. When the wind blows against the outer louvers of the vent, it creates an upward draft, allowing air to flow out freely. Even the gentlest breeze can create exhaust ventilation. The Aura Gravity Ventilator also leverages the Stack Effect to enhance roof ventilation. The Stack Effect occurs when hot air naturally rises and escapes through the roof vent. One of the major drawbacks of traditional roof wind turbines is their susceptibility to worn-out bearings, which lead to malfunctioning or even seizing over time. Not only does the Aura Vent withstand the test of time, but it also remains fully operational. Its vertical louvers act as a barrier against rain, snow, insects, and animals, ensuring that only air flows through the vent. The Aura Gravity Vent is designed as a retrofit or a vent for a new roof: UL Listed, Texas Department of Insurance & Florida State Approved. One of the standout advantages of the Aura Gravity Vent is its maintenance-free operation. Unlike traditional roof wind turbines that require regular inspections, lubrication, and potential repairs, this vent's design eliminates the need for such upkeep. Upgrade your roof ventilation system with the Aura Gravity Ventilator and experience the difference it can make for your home. Color: Green. Material: Aluminum.