BOYA BY-WM5 wireless microphone is for use with DSLR cameras, camcorders. The 2.4 GHz GFSK system result in strong anti-interference, good security and stability. Two-way communication, but only sound from transmitter can be recorded.The operation range is 50m without obstacle, 360 degree all-round revolveis workable, the maximum distance can reach up to 80m. You can adjust the volume through VOL+ and VOL- volume control. The lapel clip makes it easy to carry.