These are silver conductor cables, soldered with silver solder and use silver plated connectors. Did I mention silver?

XLR, RCA and even BNC cables of the same construction are available.
Shielded phono cables are also available.

There's also the special silver/gold foil and tinned copper in cotton hybrid cable available. 

These are more affordable alternatives.

• Mundorf ACW in cotton

An excellent choice for those who prefer a slightly meatier presentation compared to the silver cables, while keeping most of the resolution of the silver cables

• Tinned copper in XLPE or PTFE

A special sound. More body, however not quite as warm as the Duelund DCA range of wires. Yet also never harsh.
Transparency does take a hit, but it can be very synergestic with some setups.