The power supply voltage supports between DC 6V and 18V, and the current is between 1 and 1-2A. Voltage below 6V is not supported. You can connect the speaker directly. Support the song format MP3/FLAC Main functions: MP3/USB/TF/LINE IN/FM/Bluetooth/remote control The power is 50W, and the stereo is 2*25W. Product power supply voltage:6V-18V Product size: length 124MM x width 34MM x thickness 53MM 2 screw hole distance 24 mm x 113 mm Function description: 1. Bluetooth version 5.0 2. Support 6.5MM microphone 3. Support KARAOKE mode of music accompaniment. 4. Support the call ( the pause button to answer the call for a long time). 5. Support recording. Recording only supports TF mode or USB mode. ( and hold the MODE button to start recording, and hold the MODE button again to cancel recording and play the recording file; Exit the recording mode and the pause button for a long time to exit. When recording, you need to connect a storage device, such as a USB flash drive or TF card) 6. Support power-off memory. Color:As Shown Material:plastic Package Contents: 1set * 2x25w bluetooth decoder board audio 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.