Type: Headset Speaker Diameter: 40mm; Sensitivity: 108dB with tolerance of 3dB; Frequency Response: 15Hz-20, 000Hz; Impedance: 32ohm; Rated Power: 20mW; Power Cability: 200mW; Cable Length: 2.3Mwith tolerance of 0.15M; Plug Type: Stereo 3.5mm Notes: 1) High quality handband pad and comfortable ear cushions make these headphones best suited for extended usage; 2) The headphone utilizes high grade coiled Oxygen-free for speedy transfer with minimal loss; 3) With the adjustable Mic unit manufactured in dust-free workshop and the the use of noise-proof spiral shield wire, the handphone significantly isolates background environment noise, making smooth and clear communication possible at any time and any place; 4) Head pad, ear pad adopts advanced porosity genuine leather; 5) Adopt 40mm Neodymium magnet driver unit, which can have a perfect performance from undertone to alt; 6) All raw materials including working process complies with EU ROHS directive. And we can provide relative test report issued by authority, which ensure a safe secure use.