Add two RS232 serial ports with COM retention to your laptop or desktop computer through USB 2 Port USB to Serial RS232 FTDI Cable Adapter with COM Retention USB to RS232 Adapter / USB to DB9 Adapter / USB to Serial Adapter / USB Serial Cable / USB to RS232 Serial - Easy installation and operation / COM port retention provides robust connectivity for serial devices Portable & USB-powered Perfect for IT Admins - Add RS232 ports to newer computers Supports baud rates up to 921.6Kbps