The Signature XL speaker cable is the latest version of Chords longest running & most loved products. The Signature was the first high-frequency shielded speaker cable released by Chord & was a massive leap forward in cable performance. Previously PTFE insulation (Teflon) was used. Now Chord uses Taylon. Although its expensive Taylon really will enhance the listening experience & improve the performance of your cables. This is why Chord have used this in their signature range to provide the best quality cables for your system.