sony MDRZX310-LQ Foldable Headphones - Metallic Blue Folding mechanism of its own that can be compact size Quick folding mechanism adopted simple, easy to carry Model: Dynamic Sealed Driver diameter: 30mm Playback frequency: 10 ~ 24000Hz Impedance: 24 Output sound pressure level (sensitivity): 98dB Plug: 3.5mm stereo mini plug Code: 1.2m Weight: about 125g I (except cable)