Features: brand new and high quality Volume adjustment: high-end encoder knob adjustment, smooth feel. Protection mechanism: overvoltage, undervoltage, overheating, DC detection, short circuit protection. Note: When the audio signal input is large enough and the power supply voltage/current is large enough, there will be enough output power! The higher the power supply voltage, the greater the output power, the smaller the horn impedance, and the greater the output power! Please ensure that the power of the adaptive power supply is greater than the actual working power of the power amplifier! Specifications: Product name: 2.1 channel Bluetooth-compatible audio amplifier module Product model: YS-TB21S Bluetooth-compatible version: 5.1 Input mode: Bluetooth-compatible+AUX+USB disk+USB sound card Number of channels: 2.1 channels (left and right channels+subwoofer) Power supply: DC12-24V ≥ 8A Input sensitivity: 500mV Output power: left and right channels ≤ 50w subwoofer ≤ 100W Adaptive speaker: left and right channels 20-50W 4-8Q subwoofer 20-100W 4-82 Special function: support YS Audio APP control Product size: approx. 118x100x23mm/4.65x3.94x0.91in Package Includes: 1PC x Power Amplifier Board note: Please allow 0-1cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you!