Adapter power supply: working voltage range 10-30VDC, limit 31V. It is recommended to use a DC power supply with a voltage of 24-30V and a current of more than 10A. The higher the voltage, the greater the output power. Never connect to AC power, otherwise it burn out! Adapter speaker: 3-8 ohms, 20-100W in BTL dual-channel mode; 2-8 ohms, 50-200W in PBTL mono mode High current, low magnetic loss, small parasitic capacitance, low heat generation, use of oxygen free copper wire to improve sound quality; The magnetic shielding mechanism has strong anti electromagnetic interference performance. Thickened heat sink, silent and long-life fan; Solved the heat dissipation problem and better utilized the advantages of high power Transparent sound, fast low-frequency response, strong mid frequency texture, high frequency smoothness, and minimal loss Product model: -2001 Colour:Black Material:PCB Package Contents: 4x power amplifier board 4x 3P double-ended shielded cable Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.