To listen to your music without disturbing anyone.Very light, you can take it everywhere with you: at school, on holidays…You can adjust the size so that it fits perfectly on your head!Handy folding design: you can store it easily in your bag!Frequency response: 20 - 20,000 HzImpedance (acoustic resistance): 32 ohmSensitivity: 85 dB. Volume control to protect your ears!Compatible with all audio and video players with headphones jack output.Power output: 9mW x 2.