Tripp Lite USB to Serial Adapter Converter RS-422/RS-485 USB to DB9 2-Port - External - USB Type B - Linux, Mac, PC - 2 x Number of Serial Ports External

Independent DIP switch controls provide easy port configuration 2-year limited warranty Automatically reassigns COM values to each port to avoid additional configuration USB to serial converter lets you connect two 9-pin serial devices to your computer or laptops USB-A port. Auto-detects and -switches RS-422 and RS-485 serial devices Compatible with Windows, Mac and Linux-works with most computers USB-powered, so no bulky or obtrusive external power supply is required