Facmogu XH-M139 TPA3116D2 Amplifier Board, 50WX2+100W 2.1CH Digital Power Audio Amplifier Board Subwoofer Speaker Stereo AMP Module Noise Cancelling Free Sound Adjustment Power Amplifier DC 12-24V

Specifications: SNR: 100db Switch frequency: 1.2MHz Signal output: 6 screw terminals Signal input: 3.5 mm stereo jack or 3-pin socket Power input: 2.1 mm x 5.5 mm DC jack Applicable speaker impedance: 4-8 ohm DC 12-24V for versatility Independent Channel Controls, if you are facing towards the face of the knobs the farthest left knob is the Left and Right channel volume, the middle knob is the Bass channel volume, and the farthest right knob is the Master volume. As for the terminals, if you are looking at the amp top down with the knobs facing towards your chest, the farthest left terminal is the left channel, the middle terminal is the right channel, and the farthest right terminal is the bass channel.