Drivers: 50-millimeter diameter with oxygen-free voice coil and neodymium magnet Driver enclosures: Dynamic closed-type with circumaural design Driver impedance: 24 ohms Sensitivity: 107 dB/milliwatts Recommended power: 3 watts (maximum) Recertified by Sony with manufacturer's warranty Frequency response: 5 to 30, 000 Hz Plug: Gold-plated stereo UniMatch plug (0.125-inch mini with 0.25-inch phono adapter with self-cleaning screw-type design) Dimensions: : 5 by 5.25 by 3.5 inches (folded) Cord length: 9.8 feet (extended) Cord design: Class-1 oxygen-free copper (highly conductive for maximum signal transmission and minimum signal noise or distortion) Weight: 10.5 ounces (without cord)