Product name: 2.1 channel bluetooth audio power amplifier moduleProduct model: -MT21Bluetooth version: 5.0 (unblocked, 15 )Input Sensitivity: 500mVInput : AUX+BluetoothNumber of channels: 2.1 channelsAdapter speaker: 20-100W, 4~8Protection mechanism: anti-reverse connection, overheating and overcurrent, short circuit protectionAdapter power supply: DC12~24V/5A or above (24V battery pack cannot be connected)Output power: left and right channels Less than 50W, subwoofer Less than 100W:1. Only when the audio input is sufficient and the power supply voltage/current is sufficient will there be enough output power!2. The higher the power supply voltage, the greater the output power, the smaller the speaker impedance, the greater the output power!3. Please that the power of the adapted power supply is the actual working power of the power amplifier!Material: PCB+Metalcolour: blackPackage Contents:1 amplifier board1 x screwdriver1 adapterOnly the above package content, other are not included.Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.