Features: Interface detailed description USB power supply: Universal Micro USB 5V power supply 3.7-5V power supply pad: Realize external 3.7-5V lithium battery power supply modification LED indicator: blue light in bluetooth mode is on 3.5mm stereo audio interface: standard 3.5mm interface, output stereo sound source, can insert earphones, connect power amplifier and other equipment Pairing instructions: Connect the power, the blue indicator light flashes, and enter the Bluetooth mode; when you hear the voice announcement "The Bluetooth device is ready to pair", it means you enter the Bluetooth mode and wait for pairing; after the mobile phone Bluetooth searches for "JH-BT", Click Connect. When you hear the voice announcement "TheBluetooth device is connected successfully", It means that the decoder board is successfully connected to the mobile phone, and the blue indicator light is on, and the music can be played, and the blue indicator light flashes Specifications: 100% Brand New Power Supply 3.7-5V SNR 90dB THD+N -70dB Crosstalk -86dB DNR 91dB Support Profile A2DP/AVCTP/AVDTP/AVRCP/HFP LOS >15m Size30mm*30mm Package Includes: 1 xBluetooth Receiver Note: Please allow 0-1cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you!