This is a Bluetooth audio receiver module, which means it can receive the audio signal of MP3 and other popular formats. It’s very easy to connect and operate, and once connected to the other Bluetooth device like your phone or laptop etc. it can receive the signal and convert it into the output form which is compatible with the speakers. It has 3 output terminals  L Out, R Out and GND to which you can directly connect your wired earphone using a 3.5mm female jack or if you want to drive a big speaker you can connect its output to the input of a good amplifier system. It can be used to drive the Feature & Specification : Bluetooth 3.0 with audio signal decoding feature. The output is directly compatible with the amplifier. Very little weight and small size form factor make it easily fits into any application area. Can be used to Design your own wireless music system Low power consumption. 3.7v-4V voltage supply.