This is an in-ear headphone that uses clever technology with an external bass unit acoustically connected to a stream duct to improve bass reproduction without interfering with the medium and high frequency ranges. Mid-high frequencies are reproduced through twin drivers with strong neodymium magnets, using a combination of a carbon nanotubes diaphragm and a carbon diaphragm. The 1.2m cable consists of pure copper covered with silver and the 3.5mm mini jack is gold plated. The resulting sound is of an exceptional quality level with deep impressive bass that never superimposes its impression on the transparent mid-high range. The JVC HA-FXZ200 is a very valuable upgrade to the low quality headphones supplied with many mobile devices and will, without doubt, significantly improve the music listening experience on the go.