Working Voltage:DC 3.7V~5VV Bluetooth Version:4.2version Class:D Class Output:5W+5W Speaker:4ohm~8ohm 3W~5W(Don' Include!).:90dB. +N:-70dB. Crosstalk:-86dB. DNR:+91dB. Support Profile:A2DP/AVCTP/AVDTP/AVRCP/HFP. LOS: 15m. Work Temperature:-40 ~85 Celsuis. Work Humidity:0%~95%RH. Size:38x38x7.5mm Using Steps 1.Connect 2pcs 4ohm~8ohm 3W~5W speaker at "R_OUT" and "L_OUT".Or connect to a speakers from 3.5mm audio output interface. 2.Connect right power supply at Micro-USB or PCB silk screen at "3.7-5V". 3.Then the Blue LED indicator will keep ON.It means module enter into Bluetooth mode. 4.Then module broadcasts a tone, which means waiting for pairing. 5.Open Bluetooth at phone and it can search for Bluetooth device "".Click "" to connect module.When the tone is heard again, it means that the pairing is successful.Please turn off Bluetooth, remove power, re-pair, if pairing fails. 6.Playing! Note: During use, the mobile phone and the Bluetooth decoder board must not be blocked by obstacles such as walls, and should be away from the metal shield as much as possible; blocking will reduce the transmission distance, and in serious cases, music playback and intermittent problems will occur.The angle between the decoder board and the mobile phone can be appropriately adjusted to adjust the optimal state of the connection signal. Application:1.DIY speaker. 2.Voice intelligent control. 3.Bluetooth signal conversion. 4.Stereo Bluetooth speaker. 5.Stereo Bluetooth headset. 6.Bluetooth hands-free calling. 7.Bluetooth control. 8.Multi-media equipment Colour:red Material: ABS Package Contents: 5 x Bluetooth MP3 Decoder Amplifier Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.