Design from WADSN
1.Function: pick up and noise reduction
2.Noise reduction value +NRR 22dB
3.When the volume exceeds 82DB, it will reduce automatically  to a safe volume
4.With 5-level volume adjustment function
5.It will shut down automatically after 2 hours of no operation
6.Detachable microphone for both lefty or righty assembly
7.With connecting line
8.Can work with helmet adapter (WZ219)
9.Powered by 2pcs 1.5V AAA batteries