The Liztek USB to VGA Video Graphics Adapter Card for Multiple Displays allows you to connect three or more monitors to your laptop or desktop PC. You will need one adapter per monitor and can connect up to 6 total monitors on Windows PCs. The Liztek USB to VGA Video Graphics Adapter Card for Multiple Displays works with Windows 8.1/8/7 32/64 and XP 32-bit drivers via Windows Update, download, or disk. The Liztek USB to VGA Video Graphics Adapter Card for Multiple Displays does not support Mac 10.9 “Mavericks” due to significant limitations in the operating system. Linux beta-quality drivers available but with important limitations