Very light, you can take it everywhere with you: at school, on holidays, in the car. You can adjust the size so that it fits perfectly on your head and listen to you music without disturbing anyone. Handy folding design: you can store it easily in your bag. Frequency response: 20Hz-20kHz. Impedance acoustic resistance: 32 Ohm. Sensitivity of 85 dB to protect your hearing. Compatible with all audio and video players with a headphones jack output.