1. Best Ventilation Solution: Designed to fit 8' whirlybird turbine roof vents, round chimney caps, and roof vent caps, this roof vent adapter enhances ventilation in shipping containers or container storage, reducing moisture and heat to help protect stored cargo. 2. Precision Fit for Conex Roof: This container accessory is designed for Conex container roofs with a 3.5" rib profile to help prevent leaks when retrofitting the ventilation system of a container house. Please measure your roof rib size before purchasing. 3. Roof Vent Kit: Includes positioning aid sticker, driver bit, and drill bit. The corrugated base design allows secure installation on the Conex box roof without welding. 4. Excellent Weather Resistance: This roof turbine vent adapter is made of high-quality steel with a powder-coated, rust-resistant finish for durability and performance in harsh weather conditions.