Two different interfaces:

1， mono interface， suitable pockets loudspeakers and bright sound with QCT-01.

2， stereo interface， suitable PureFM-980 wireless teaching machine， and computer use.

Frequency response: 50Hz-20KHz

Impedance: 2.2K Ohm

Mi head size: Ø6.0X5.0mm

Sensitivity (sensitivity): - 58dB ± 3dB (0dB = 1uPa)

Direction: the whole point

Plug: 3.5mm stereo silver pins

Wire diameter: 2.0MM

Cable length: about 1.2m