The potentiometer adjusts the volume with a switch for easy control of the volume, making it Perfect for DIY speakers.If it is a metal box, you need to bring out the Bluetooth antenna. The copper DC connector is used to withstand high current and no heat. Capacitor 470uf35V solid capacitors power storage and heat dissipation, and stable power supply is a prerequisite for good sound quality. Free DC head lead, compatible with the input power interface of this product, even if you 't have a DC head adapter or battery, it can be wired. 5.0 Bluetooth version, the transmission efficiency is higher, the transmission distance is farther. Colour: Black Material: PCB+Plastic+Metal Precautions for use: The power switch on the board is the standby switch. After the switch is turned off, the machine is in a low-power standby state. To completely turn off the power or unplug the DC plug on the machine for a long time. Product Name: Dual channel Bluetooth 5.0 power amplifier board Input voltage: DC5-27V Bluetooth Version: 5.0 Output impedance: 4~8 ohm Speaker For Speakers: 30W~200W Output power: 50W x 2 Audio input: Bluetooth Number of channels: two channels Size: 55 x 38 x 17MM Question and : How to connect to Bluetooth? Power on the power amplifier, connect the speaker, turn the audio knob blue light to turn on, turn on the phone settings - Bluetooth - search for "BT-WUZHI", and then click the connection, there will be a beep when the connection is successful, this When it is in Bluetooth mode, you can . The time you power on, it will automatically connect with the phone. Package Contents: 1 amplifier board 1 x DC wire 1 shell material package 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.