Duct Connector Flange is used for seamless connection of duct systems to reduce air leakage Material: Galvanized Steel Color: Silver Size : 6.3" x 6.3" x 1.2 Inch Opening diameter: 4" Inch Features: 1. Ensure seamless connection, reduce air leakage, and enhance airflow 2. Made of galvanized steel, sturdy and durable, good sound insulation effect 3. Smooth surface without burrs, reducing the risk of hand and finger scratches 4. Easy to install and disassemble