This duct collar is used for connecting air ducts, including metal spiral pipes, hoses, PVC pipes and so on. It is suitable for bathroom fans, extractor fans, tumble dryers, in-line extractor fans, HVAC systems, dust collection systems, hydroponics installations and so on. They are widely used in homes, offices, kitchens, warehouses and apartments.Specification:Color: SilverMaterial: galvanized ironSize: 65 x 0.6 mm/2.56 x 0.02 inches (H*W)Interface OD: 300 mm / 11.8 inchesDiameter: 320 mm / 12.6 inchesPacking list: 1 piece x Duct CollarAdvantages:1. made of durable galvanized iron material, sturdy, waterproof, moistureproof, wear-resistant, good toughness, strong pressure resistance, not easy to deform, can be used for a long time;2.