The module stereo output, built-in Bluetooth antenna structure is simple, the supply voltage of 3.7V or 5V power supply options, can be used as an ordinary amplifier, active speakers to increase the Bluetooth connection function. 7PIN output interface for the pitch 2.54mm, 7PIN output interface:   power, ground, left channel, right channel, mute, LED status indication, reserved port. Which LED state port, an external 100 ohm resistor in series LED indicator connected to the ground, Bluetooth is not connected for fast flash, Bluetooth connection after the success of slow flash.