It's a DC 12V 24V TPA3116 2.0 Dual-Channel Digital Amplifier Board, Voltage range: DC 10~25V, Output load: 4~8 Ohm (Recommend), Recommend for adequate power supply (the current must be large enough), otherwise it cannot give play to the power of amplifier and speaker. It has small size, high efficiency, long term stable and reliable quality,easy installation and use. Very easy to connect,and enjoy diy fun.