We're the manufacturer of headphone, earphone, flash card, and MP3/4/5

 Speaker Dimension: 30mm

. Impedance: 30Ω

. S.P.Lat: 1KHz  . Sensiticity: 105Db

. Frequency response: 20Hz-2000Hz

. Pat power: 100mw

. Power capability: 10000mw

. Plug Type: 3.5mm stereo