Features: Using original XY-AP15H chip, High power rejection ratio, high AM rejection, high power conversion efficiency 4 audio input mode: Bluetooth / AUX / USB-C disk / USB-C sound card App control , it can be used to switch audio input mode / play mode / sound effect Left+Right channel output (stereo) Support active and passive speakers Protection: anti-static , reverse polarity , short-circuit , over-heat , over-voltage , under-voltage, DC protection Parameter: Name: 20W+20W bluetooth amplifier board Model: XY-AP50H Chip: 1 * XY-AP15H (Class D) Input voltage: DC 5-27V / 2A above Bluetooth version: 5.0 Channel quantity: 2 (Left+Right stereo) Audio input: Bluetooth / AUX / USB-C disk / USB-C sound card Output : LC filter output, high-definition sound quality Transmission distance: more than 15meters (Unobstructed) Speakers range 10W-200W , 4/8 Output power: 10W*2@12V,8 20W*2@12v,4 Package include: 1Set Bluetooth Digital Amplifier Board Note: The protection board and heat sink need to be installed by yourself