Our package includes 2 non-power roof ventilators, each with a hoop. The vent connection size measures approximately 4.33 inches (11 cm) in diameter and 7.48 inches (19 cm) in height. It ensures quick and efficient release of hot air from the roof space within minutes while protecting against rain and moisture. The non-power roof ventilator is constructed from high-quality 201 stainless steel, ensuring durability and long-term performance. The material resists rust and withstands high temperatures, making it suitable for various weather conditions. This roof ventilator requires no electricity to operate. It functions automatically by utilizing wind and natural convection to exhaust air continuously throughout the day. This energy-efficient design provides silent, maintenance-free operation without the risk of electrical faults. The ventilator features a tube diameter of approximately 4.33 inches (11 cm) and a turbine diameter of approximately 7.48 inches (19 cm). Its optimized size allows for rapid and effective airflow, helping to prevent moisture buildup and stale air in enclosed spaces. Ideal for residential or light commercial use, this ventilator is suitable for installation on roofs in locations such as factories, farms, workshops, kitchens, and homes. It also works well with chimneys that are not frequently used, contributing to a more comfortable indoor environment. Despite requiring no electrical power, the ventilator delivers reliable and efficient air extraction within minutes. It helps protect the surrounding area from rain and excess humidity. Enjoy quiet ventilation performance with this non-power roof ventilator. Its seamless operation provides effective airflow without generating noise. Made from durable stainless steel, it offers rust-resistant and heat-resistant properties for long-lasting service. Size: Tube diameter: approximately 4.33 inches (11 cm) Turbine diameter: approximately 7.48 inches (19 cm)