External 5.1 Usb Sound Audio Box Card Adapter, Also Optical listen your surround sound audios directly from USB port of your PC or laptop.The Easiest Upgrade From Basic Built-In PC Sound To Surround Sound Audio Compatible with WIN98SE,ME,2000,XP,VISTA,MAC 0S 9.1 (Mac version has 2 channel playback only) Fully dublex playback/recording audio stream without sound card in PC Supports multi channels audio code interface for 5.1 channel playback Supports conventional audio 2 channels source playback (Only L, R channel active)