Meze Audio built their copper upgrade cables to improve signal clarity and look great alongside the Empyrean. Each cable is made of 99.99% PCUHD wire, or Pure Copper Ultra High Drawability wire, that contains less impurities than the standard cable. They're protected by a strong and rubbery TPE, or thermoplastic elastomer sleeve, that's semi-transparency lets you see the copper within. Specs 2.5 MM Balanced Source Jack: 2.5mm balanced Headphone Jack: 4 pin mini-XLR Length: 3.9 feet (1.2m) Materi