Conductor covered by the soft TPU. Coated  with fine woven mesh. 28AWG * 8 strands structure. 

Wide and thick low-frequency plus high-frequency euphemism variable high without sharp voice. 

Especially in the high-fidelity in-ear earphones.  It is said to be valuable. Its sound color performance in its rich high and low-frequency details. 

The lustre is cool. Suitable for insufficient of high-frequency or inadequate extension of the moving iron earphones.