Panasonic Sealed dynamic stereo headphones high-resolution black corresponding RP-HD10-K Format: sealed dynamic stereo headphone Use unit: diameter 50mm/Impedance: 18 Sound pressure sensitivity: 92dB / mW/Maximum input: 1,500mW Playback frequency band: 4 ~ 50,000Hz Cord length: about 1.2m / about 3.0m (detachable cord)