FeaturesLength : 163mmInstalls automatically and easy to use.USB 2.0 To Standard 3.5mm microphone and headphone jacks.Plug & play USB device for your PC or Notebook.Package included:1 pcs Logitech USB To 3.5mm Jack Audio AdapterSystem RequirementsCompatible with Windows 2000, XP, Vista, and MacOS X. Instruction: 1. Turn off your computer2. Insert the Logitech adapter into USB port of your computer3. Check whether your headphone or headset has microphone and headphone jacks. And please make sure that your headphone/headset works. Insert two jacks of your headphone or headset into the adapter jacks accordingly.4. Turn on the computer5. Open a music software or chat software, such as windows media player, then you can hear the music. If not, please change the jacks. Maybe you insert the wrong jacks.