Features -Color: Black -Material: plastic stainless steel -Size: 10.00X8.50X5.50cm/3.93X3.34X2.16in Note: random color accessory - Adopt power boost isolation technology to effectively prevent ground wire signal interference. - Built-in low-pass filter circuit design fully filter out the interference noise of external audio equipment. - start-up function to avoid the impact sound of pop when starting up. - Two sets of balanced power supply balanced input and output signals make the voltage balance and stable and suppress common mode interference. - With USB 5V boost circuit low-voltage power supply technology to prevent harm to the human body and solve the problem of unsuitability due to city voltage difference.