1、Plug and Play USB 2.0 2、USB bus-powered mode, no external power required 3、Digital class-B power amplifier inside 4、Supports 3D post tonal sound and virtual 5.1 CH sound track 5、Jack for speaker / headphone / Microphone Features: 100% brand new. USB bus-powered mode, no external power required. Digital class-B power amplifier inside. Supports 3D post tonal sound and virtual 5.1 CH sound track. Jack for speaker / headphone / Microphone. Work for Windows 2000 / XP. Compact, portable, convenient to carry. Delivery by random color. The Problem You May Have: Whether there is red light show ?if there is ,please ensure the USB has been installed successfully as show the above picture , if there is no such page show , it means the usb audio device installed fails, please try another computer . If there is no light show ,please change another USB connector to have a look . 2. When connected, the sound from the headphones is normal, but the microphone sound is very small: This is caused by the volume of micro in your computer ,please set the micro volume maxium . Package Include: 1 x USB Audio Sound Card Adapter Notes: 2. When this product is connected to the computer, wait for 5-10 seconds, the computer will jump out USB installation, the following screen will appear at w7 system. Only in this way, it represents the successfully installed, you can use.