Dual-head Mic: Built-in professional high-performance super-cardioid pickup microphone with dual-head mutual Complementary interference pickup technology ,Specially designed for the camera and high-sensitivity condenser microphone to improve the quality of the recording. Powered by 1.5V AAA alkaline battery: The new battery can be used continuously 70-80 hours. The power is green ,the microphone has entered the picked state; when the LED shows red bright, the battery is low.