MATERIALS: These cable ties are made of iron and the surface is zinc plated. USEFUL AND PROVIDE GREAT CLAMPING STRENGTH: Double wire cable ties are very useful and provide great clamping force. br />SMOOTH EDGES: The smooth edges of the round wire are harmless to hands or pipes. STRONGER: The double iron wire is stronger and can be used for long-lasting fastening. CONVENIENT TO USE: Convenient to use, just loosen and tighten the screw to adjust the clamp diameter. he Double Thread Steel Pipe Clamp Adjustable Steel Pipe Clip Screw Assortment Kit. Made of high quality stainless steel. colorized galvanized surface. Improves corrosion resistance and anti-resistance capability. Adjustable band range: just loosen or tighten the screw to adjust band diameter range. Prevents extrusion of the pipe with the hose clamp. ideal for industrial or domestic use. helps reduce pressure and protect hose.