Power Supply 3.7-5V. SNR 90dB. THD+N -70dB.Crosstalk -86dB.DNR 91dB. Support Profile A2DP/AVCTP/AVDTP/AVRCP/HFP. LOS >15m.Interface details:USB powered Universal Micro USB 5V power supply.3.7-5V Supply Pad External 3.7-5V lithium battery power conversion.LED indicator Bluetooth mode long blue light.3.5mm stereo audio interface Standard 3.5mm interface, output stereo sound source, plug in headphones, connect amplifiers and other devices.Instructions:After the power is turned on, the blue indicator lights up and enters the Bluetooth mode; the English The bluetooth device is ready to pair is displayed, indicating that the Bluetooth mode is entered and waiting for pairing; the XY_BT searched by the mobile phone Bluetooth is the device name of the decoding board. , Click on the connection, the decoder board prompts "The bluetooth device is connected successfully", indicating that the decoder board and the mobile phone are connected successfully, you can play music. Package Contents:1X 3.7-5V Mini Bluetooth MP3 Decoder Board Power amplifier Board Bluetooth 4.1