Specifications:
1.  Speaker diameter:Ф40mm
2.  Impedance :32?
3.  Sensitivity:118dB±5dB/1KHz
4.  Frequency response:20HZ-20,000HZ
5.  Rated power:50mw
6.  Max power:100mw
7.  Audio cable:1.3m, Ф3.5mm stereo
8.  Battery :300mAh
9.  Standby time:70 hours
10.Working time: 15 hours continuously
Functions:
1. Built-in low power dissipation audio amplifying circuit, which can improve timbre and enhance low-frequency gain.
2. With clarity timbre, and transparent sound.
3. Built-in rechargeable lithium battery, which last long  standby time.
4. Include an audio cable, which can connect to other device with audio ouput(such as Mp3, Mp4, MID, Computer, smart phoneetc).
5. Comfortable and easy to operate.
6. Ultra-soft padding and lightweight adjustable headband provide extreme comfort for long term wear