Product Description Hear uncompressed audio wirelessly with the Sony MDR-HW300K headphone system. The large 40mm driver units with neodymium magnets deliver broad, balanced, and accurate sound for an exceptional wireless listening experience. The built-in, rechargeable Lithium-Ion batteries provides up to 10 hours of continuous playback or enjoy the convenience of passive mode without charging the battery using the included stereo connection cable. Enjoy wireless audio convenience and comfort with MDR-HW300K digital stereo headphones. With its 40mm dynamic driver and high energy neodymium magnets, it delivers precise and powerful sound reproduction up to 10hrs. Features: 1) 40mm dynamic driver for high quality audio, 2) High energy neodymium magnets deliver powerful sound reproduction, 3) Slider headphone design, 4) Pressure-relieving luxury ear cushions for extended comfort, 5) Up to 10hrs of playback enjoyment. Specifications: Type: Closed, Dynamic, Driver Unit: 40 mm, Sensitivity: 98dB/mW, Power Handling Capacity: 1,000 mW, Impedance: 32 ohm, Frequency Response: 10Hz-22,000Hz, Diaphragm: PET, Magnet: Neodymium, Plug: Stereo mini Jack, Power Source / Battery Type: Built-in Lithium ion Rechargeable Battery, Battery Life: Approx. 10 Hours (fully charged), Battery Charge Method: USB charging, Battery Charging Time: Approx. 3 Hours, Volume Control: Yes (Tact), Frequency Modulation: GFSK, Carrier Frequency: 2.406GHz-2.478GHz, Signal Reception Distance: 30m (max), Distortion: 1% or less, Audio Input(s): Analog (Stereo mini plug), Supplied Accessories: AC Power Adaptor(1), Connection Cable (1), USB Cable (1).