Four conductor: 15 foot (450cm) extension cable terminated with a 3.5mm plug and a 3.5mm jack.

The cables are constructed from the same high quality super annealed copper wire as the X-Series headphone cables, with braided sheathing. For longer lengths cables may be piggybacked up to 3 cables. Grado guarantees no degradation of sonic quality with Grado headphones while using their extension cable.