2 XLR/6.35mm interfaces at the input end, balanced, Output: 1 3.5mm headphone jack Input impedance 20 kilohms Frequency response 20Hz-80kHz Total harmonic distortion + noise 0.01% Signal-to-noise ratio 90DB Front panel: The headphone output port can accept a 3.5mm headphone plug. Battery statues indicator light shows the current battery life (the indicator light becomes lighter when the voltage is too low) The VOLUME knob adjusts the headphone output sound volume. The Balance knob adjusts the balance between the left and right channels of the input terminal. The Mode button selects whether the audio connected to inputs INPUT(L) and INPUT(R) is mixed in stereo or mono. In Stereo mode, audio connected to INPUT(L) is sent to the left earphone, and audio connected to INPUT(R) is sent to the right earphone. In mono mode, the audio connected to INPUT (L) and (R) is sent to the headphones on both sides, and the volume between the two audio sources can be adjusted using the Blanc knob. Rear panel: Power button turns power on and off INPUT(L) receives the signal through the XLR/6.35mm cable. In stereo mode, the signal is sent to the left channel INPUT(R) receives the signal through the XLR/6.35mm cable. In stereo mode, the signal is sent to the right channel. Plug Type:EU Plug,it applies to Indonesia, Germany, France, Spain, Italy and so on. Voltage:AC100-240V Colour:Black Material:Metal Size:About 125x86.5x35mm Package Contents: 1 x Headphone Amplifier 1 Adapter 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.