Brand: Avantree. MPN: HF2039. Wired Headphone • Speaker Size: 40mm • Frequency Range: 20Hz~20kHz • Sensitivity: 97±3DB • Impedance: 32 ±15% • Cable Length (fully extended) : 5m±0.1m DAC Input Audio: Coaxial or Optical digital audio Output Audio: R/L and 3.5mm audio Sample Rate: 32 44.1 48 and 96 KHz Max Working Current: 250mA Power Adapter Format: Input: AC (50Hz 60Hz) 100V-240V; Output: DC 5V/500mA Dimension (L x W x H): 45x48x20(mm) Weight: 62g.