1. Working voltage: 3.7~24VDC2. Bluetooth version: 5.03. Transmission distance: 15 meters (visible without obstruction)4. Signal to noise ratio: greater than or equal to 90dB5. Distortion: less than or equal to -70dB6. Number of channels: dual channel (stereo)7. Audio interface: 3.5mm audio interface8. Module protection mechanism: Power reverse connection protection9. Interface description:- Power supply can use Micro-USB mobile phone charger, 3.7-4.2V lithium battery, 3.7-24V DC power supply, you can choose one of the three.- Short the "on/off contact" for 2 seconds to set the decoder board on/off. For battery-powered situations, turning off when not in use will save power and facilitate modification.

http://olla.gr/2-pcs-xy-wrbt-bluetooth-5.0-decoder-board-stereo-audio-module-wide-voltage-speaker-amplifier-with-remote-control/