These round tubes are brass, very strong but light weight. Each size telescopes into the next corresponding size. For use in plumbing, HVAC and automotive. It can be soldered, glued, polished, cut and bent to whatever shape required. UPC: 614121181397 Manufacturer Part No: 8139 Brand Name: K&S Diameter: 1/2 in. Shape: Round Length: 12 in. Product Type: Brass Tube Number in Package: 1 pk Application: Scratch builders, modelers, crafts, machine shops and architectural Wall Thickness: 0.014 in. Packaging Type: Carded Finish: Mill California residents see Prop 65 WARNINGS