Grado offers a 480cm extension cable terminated with a 1/4 inch 6.35mm plug and a 1/4 inch 6.35mm jack. This cable is constructed from the same high quality wire as their headphone cable, and contains 4 conductors. For longer lengths the cable may be piggybacked up to 3 cables. Grado guarantees no degradation of sonic quality with Grado headphones while using their extension cable.