Closed dynamic in-ear earphones. Hand-made by highly skilled engineers in Germany and features high-grade silver-plated fiber cables with coaxial construction, and a voice-coil made by Beyerdynamic. Allows user to experience an extremely wide frequency range, with crisp bass, well-balanced mids and crystal-clear highs. Includes standard 1,3 m cable with general purpose 3,5 mm plug, balanced cable for Astell & Kern devices with balanced output and specific 2,5 mm 4-pole terminal, and a leather case for safe transport. Frequency response: 8 Hz - 48 kHz. Impedance: 16 Ohm. Max. SPL: 10 mW.