
High-Quality 70 mm Galvanized Flat Duct ISO 9001 Certified. ISO 9001 & CE Certified: Product meets international quality standards with ISO 9001 and CE certifications. Customizable Length: Length is customizable, typically 5.8m per piece, adjustable to customer needs. Hot-Dipped Galvanized: Made from galvanized steel strip with strong durability for concrete casting. Free Samples Available: Free samples provided, buyer only covers express shipping costs. In-House Manufacturing: Ducts are produced in-house by our own factory workers for quality control. High Radial Stiffness: Features high stiffness and leak-proof performance for post-tensioning. Fast Delivery: Standard delivery within 20 days after receiving deposit or L/C. 100% Pre-Shipment Test: Every product undergoes 100% testing including axial tension and salt spray tests.