Features:_x000D_ _x000D_ Adopting high performance amplifier chip, practical and durable. _x000D_ Maximum 50W(left channel) + 50W(right channel) dual channel output, efficiency up to 90%. _x000D_ The power interface is the standard 55mm power jack, like most laptop power. _x000D_ Can use switching power supply, laptop, battery or car power supply, etc. _x000D_ Suitable for a variety of different amplifier powers. _x000D_ _x000D_ Specification:_x000D_ Material: Electronic Components_x000D_ Weight: 62g/2.2oz_x000D_ Channel Number: Dual channel _x000D_ DC Power Supply: DC 8V-25V _x000D_ Output Power: Change with voltage and resistance _x000D_ Product Packaging: Anti-static packaging _x000D_ Size (L*W*H): 70*90*20mm/2.8*3.5*0.8inch_x000D_ _x000D_ Package List:_x000D_ 1 x Digital Amplifier Board_x000D_ _x000D_ Note:_x000D_ 1.Please connect the external power supply and the digital power amplifier connection port first, and then connect the 220V power cord of the external power supply into the socket. _x000D_ 2.The output power will be sufficient only if the audio input is enough, the power supply voltage/ current is sufficient. The power supply voltage is high, the relative power will be large, the speaker with different impedance will have different output power. When the voltage current is sufficient, the greater the horn resistance, the smaller the relative sound power.