The boya by-m1 lavalier microphone is suitable for all devices equipped with a 3.5 jack microphone input, such as smartphones, computer, audio recorders, amplifiers etc. the cable has a length of 6 meters and the microphone can easily be clipped onto your clothing, providing you with the freedom of movement. these features make the by-m1 very suitable for use while walking, during a speech, for use during a lecture or even for hands free calling. the included lr44 battery does not need to be used when using the by-m1 with a pc, laptop, tablet and smartphone. only when used with certain recording equipment, such as audio recorders, the battery needs to be used. when used with a pc/laptop, the device must have a 3.5 mm combo port, for both headphones and microphone. Boya by-m1 lavalier microphone specifications - transducer: electret condenser - polar pattern: omni-directional - frequency range: 65 – 18.000 hz - signal/noise: 74db spl - sensitivity: -30db +/- 3db / 0db=1v/pa, 1khz - output impendence: 1000 ohm or less - battery type: lr44