our package includes 2 non power roof ventilators, each with a hoop; The vent connection size details to about 4.33 inches/ 11 cm in diameter and 7.48 inches/19 cm in height; It ensures quick and proficient release of roof air in just a matter of minutes while securing your space against rain and moisture the non power roof ventilator is exclusively constructed with the quality 201 stainless steel, assuring you of its and sturdiness; The material does not only resist rust but endures high temperatures as well, perfect for challenging weather conditions our non power roof ventilator does not require any electricity to operate; Instead, it automatically exhausts air throughout the day; Avoid extra expenses and the worry of short circuits with this energy conservation solution that offers continuous and noiseless operation the ventilator comes with a tube diameter of about 4.33 inches/ 11cm and a turbine diameter of about 7.48 inches/ 19cm; Its perfect size assures quick and efficient air release while keeping your space free of moisture and stale air this ventilator is your reliable companion for residential use or light commercial applications; It's perfect for spaces like factories, farms, production workshops, kitchens, roofs, and houses; The easy air flow makes it a suitable choice for chimneys not frequently applied, ensuring a comfortable environment Despite requiring no electricity for operation, the ventilator assures quick air release in minutes. Reliable and efficient, the ventilator secures your surroundings against rain and excess moisture. Enjoy silent operation with our non power roof ventilator. Its seamless operations quick air ventilation without creating excessive noise. Made from quality Stainless Steel, you can rely on its rustproof and heat capacity to provide years of efficient service. Size: Tube diameter: about 4.33 inches/ 11 cm Turbine diameter: about 7.48 inches/ 19 cm Height: about 7.48 inches/19 cm Colour:Silver Material:Stainless steel Package Contents: 1 set x roof vents for houses Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.