set of 2 headset microphone, flexible wired boom for voice amplifier,teachers, speakers, coaches, presentations, seniors and more, black jeteho <b>features:</b><b></b><br /> microphones size: φ9.7×5.2mm<br /> sensitivity: -52db ± 3db <br /> directivity: unilateral directivity<br /> operating voltage: 2.0v <br /> impedance: 2.2k <br /> frequency range: 100-16khz <br /> snr: greater than 60db<br /> cable:90cm/35inch<br /> plug type: 3.5mm<br /> color:black<br /> package list:<br /> 2 x headset microphone<br /> <br /> headset microphone using tips <br /> 1.directional microphone, make sure the microphone above holes (sponges can be seen taking down) alignment mouth<br /> 2..distance from the mouth of the most suitable microphone is 10-15mm <br /> 3.put the microphone plug into the corresponding socket on the host (and not into the audio input jack hole) <br /> 4.before weraing the ear-hanging micropone,please don't turn on the power and volume<br /> 4.try to avoid multiple plug microphone plug, so as not to cause poor contact <br />