1. Best Ventilation Solution: Designed to fit 8' whirlybird turbine roof vent, round chimney cap, and roof vent cap, our roof vent adapter enhances ventilation in shipping containers or container storage, reducing moisture and heat, and protecting cargo stored inside. 2. Precision Fit for Conex Roof: This container accessory is designed for Conex container roofs with 3.5' rib, helping prevent leaks and allowing for retrofitting the ventilation system of a container house. Before purchasing, please measure the size of your roof rib. 3. Roof Vent Kits Save Time and Money: Includes positioning aid sticker, driver bit, drill bit, and other installation components. The corrugated base design allows secure attachment to the Conex box roof without welding. 4. Excellent Weather Resistance: Roof turbine vent adapter made of high-quality steel with a powder-coated, rust-resistant finish to withstand harsh weather conditions. Heavy-duty design ensures long-lasting durability.