1 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.2 Replacement audio Upgrade cable with 4-pin XLR Balanced Male Walnut Wood Shell 6N OCC Copper Silver Plated Cord 4-pin XLR Balanced Cable Compatible with Sennheiser HD650 HD600 HD580 HD660S HD58X HD565 HD545 HD535 HD525 Massdrop HD6XX headphones Extension Cords3 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 Cords4 4 Connector: 4-pin XLR Balanced Male to the jack for HD650 HD600 HD580 HD660S HD58X HD6XX headphones5 the connectors shell are made of the walnut wood / Solid Wood - Walnut + Brass Gold Plated