Furukawa High-quality 5N 99.999 Pure Silver Litz head-shell lead wire.

Color coded 

30 AWG 5N Pure Silver Litz wire is the best wire for faster transmission speeds, lossless data and cleaner sound. 

It's 0.55 mm outer diameter, litz construction 7 strands and each strand is 0.1mm diameter 99.999+% Pure soft annealed silver wires in oversize PTFE Teflon insulation.