HW-770 - BT Name HW-BT - Female Voice English Notification Parameter characteristics + Power Supply 3.7-5V + SNR 90dB + THD+N -70dB + Crosstalk -86dB + DNR 91dB + Support Profile A2DP/AVCTP/AVDTP/AVRCP/HFP + LOS gt;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, can connect directly to headphone or to Amplifier. Note : If using battery, Micro USB not for charging the battery, choose one option the power supply. Operating specification: When power on and blue led is on, it goes into Bluetooth mode and it is ready to pair. The device named “XY_BT” Cell phone searched is the decoding board device.Connecting the “XY_BT” device with cell phone, the decoding board plays “The bluetooth device is connected successfuly”, the decoding board has connected with the cell phone successfully, and you can playing music through the bluetooth device. Showing in the below picture . Package: 1 x Mini Bluetooth 4.1 Audio Decoder Board MP3 Lossless Amplifier Circuit board