1. [Plug and play] Connected to the device interface can be used, without external power supply, simple operation 2. [Separate volume control] with output volume control, you can adjust the ideal volume according to your preferences 3. [XLR Stereo input] The XLR input connection has a locking structure in case of accidental cable disconnection. Just the label next to the bottom mounting connector to release the cable at 4. [Standard 3.5MM headphone output] Metal 3.5MM headphone output interface can be easily connected to conventional earbuds or professional headphones, bringing you a clear music experience 5. [Small and easy to carry] You can put it in your pocket, clip it in your jacket pocket/backpack strap or use a lanyard to easily hang it on your chest Interface:3.5mm/XLR(XLR connector not included in package) Colour:Black Material:iron Package Contents: 1 x Headphone Amplifier 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.