The inside cable is made of the 6N OCC copper Single Crystal Silver Plated wires, each side include 2 strands *(0.08mm*25 cores + 0.08mm*37 cores) 6N OCC copper Single Crystal Silver Plated wires, that Superb Premium Wire, Independent Shield among L, R . Soft enough and comfortable ; the outside cable is made of the Black Thermostable Braided Tangle-Free cable, which has excellent temperature resistance range: -65℃~300℃ Connector: 6.35mm Male,the connectors shell are made of the walnut wood / Solid Wood - Walnut + Brass Gold Plated Cable Length: 2meters(6.6ft); cable diameter: The diameter of the main body cable is 5mm. And the diameter of the branch cable connected to the earphone is 3.2mm. Package include:1*replacement cable This replacement cable is compatible with Sennheiser HD650, HD600, HD580, HD660S, HD660S2, HD58X, HD565, HD545, HD535, HD525, HD265, Massdrop HD6XX headphones The 6N OCC copper Single Crystal Silver Plated wires provide clear sound, and a protective layer is added to eliminate noise interference problems, you will enjoy matchless HiFi sound and maintain original sound quality of your headphone, Extension Cords