Superlux HD-660 Pro, Headphones, Circumaural design, Closed-back, Dynamic, Drivers: 40 mm, Neodymium magnets, Max. SPL (sound pressure level): 92 dB, Impedance: 150 Ohm, Frequency response: 10 - 30,000 Hz, Single-cable configuration, Cable length: 2 m, Weight: 323 g, Includes an adapter to 6.3 mm stereo jack