Compact and portable appearance FOR DIGITAL SUPER BASS SOUND Built-in Microphone Earphones Impedance: 32 Ohms±10% Frequency: 20~20K Hz Sensitivity: 98dB± 3dB at 1K Hz Max. Input Power: 20mW Input connection: 3.5mm grade four nickel-plated stereo plug Cord Length: 1000mm±30mm Microphone Sensitivity: -58±3dB Multi--directional Frequency:100-10000Hz Operating Voltage:2.5V-10V Operating Current:<500uA Impedance:2K Ohms±10%