Single Layer Copper-coated Steel Bundy Tube/Pipe Material :SPHC, SPCD,ST-14,BHG,BCD Outdiameter :3.17mm- ... 12mm Single Layer Copper-coated Steel Bundy Tube/Pipe Features :1) Material :SPHC, SPCD,ST-14,BHG,BCD2) Outdiameter ... zinc coated are available Single Layer Copper-coated Steel Bundy Tube/Pipe