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 and heat dissipation, and stable supply is a prerequisite for good sound quality.Free DC head lead, with the input interface of this product, even if you 't have a DC head adapter or battery, it can be easily wired.5.0 Bluetooth version, the transmission efficiency is higher, the transmission distance is farther.Colour: BlackMaterial: PCB+Plastic+MetalPrecautions for : The switch on the board is the standby switch. After the switch is turned off, the machine is in a low- standby state. To completely turn off the or unplug the DC plug on the machine for a long time.Product Name: Dual channel Bluetooth 5.0 amplifier boardInput voltage: DC5-27VBluetooth Version: 5.0Output impedance: 4~8 ohm SpeakerFor Speakers: 30W~200WOutput : 50W x 2Audio input: BluetoothNumber of channels: two channelsSize: 55 x 38 x 17MMQuestion and answer:How to to Bluetooth? on the amplifier, 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 play music. The time you on, it will automatically with the phone.Package Contents:1 x amplifier board1 x DC wireOnly the above package content, other products are not included.Note: Light reflection and different displays may the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.