Supports Bluetooth 5.1 connectivity<br> Classic mechanical switch, a turn on/off without long press wait.<br> Over-temperature and short-circuit protection against static electricity<br> Support BT, AUX, U disk, USB sound card input<br> With heat sink<br> Audio Input: AUX+ Bluetooth+U disk + USB sound card<br> Channel: 2.0 (stereo)<br> Power Range: DC9-24V/4A above (high power recommended high voltage)<br> Adapter Speaker: 20W-100W, 4-8 ohm<br> Protection Mechanism: overvoltage, undervoltage, overheating, DC detection, short circuit protection<br> PS: In the audio input is enough, the supply voltage/current is enough, there will be enough output power! The higher the supply voltage, the greater the output power. The smaller the impedance of the speaker, the greater the output power! Please ensure that the power of the adaptor is greater than the actual working power of the amplifier<br> Type: Subwoofer Amplifier Board<br> Batch differences may lead to product appearance, printed text, color will be different, does not affect the use of<br> Note: Recommended with 8Q speakers, power supply 9-24VDC, not over voltage, if driving 4Q speakers, the power supply can not exceed 12V.<br> Color: Black<br> Material: PCB+metal<br> Package Contents:<br> 1 x amplifier board (need to install themselves)<br> 1 x screwdriver<br> Only the above package content, other products are not included.<br> 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.