AUXand Bluetooth audio input, HiFi sound quality, high fidelity, high-definition sound quality Subwoofer and left and right channel output External antenna available Four protection mechanisms: anti-reverse connection, overheating, overcurrent, short circuit protection Easily connect your audio system Product name: 2.1 channel Bluetooth audio amplifier module Product model: -MT21 Input sensitivity: 500mV Power amplifier chip: domestic power amplifier chip Bluetooth version: 5.0 (unobstructed, 15 meters) Input : AUXandBluetooth Number of channels: 2.1 channels Protection mechanism: Anti-reverse connection, overheating, overcurrent, short circuit protection Compatible speakers: 20-100W, 4-8Q Adaptable power supply: DC 12-24V or 5A or above (24V battery pack cannot be connected) Output power: left and right channels Less than 50W, subwoofer Less than 100w Tip: Only when the audio input is sufficient and the power supply voltage or current is sufficient, there will be enough Output power! The higher the power supply voltage, the greater the output power, and the smaller the speaker impedance, the greater the output power! Please that the power of the adapted power supply is the actual working power of the amplifier Colour:Black Material:PCB Package Contents: 1 x Upper Cover Plate 1 x Lower Cover Plate 1 x PCB Plate 1 x Screwdriver 1 Adapter 5 x Buttons 4 x M2x16 Copper Posts 8 x M2x3mm Screws 4 x M2x3and3 Copper Posts 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.