USB C to Serial Adapter Cable - USB C to RS232 Cable Adapter - USB C to DB9 Cable Adapter - Windows / macOS / Linux Compatible - USB C Serial Cable : This USB-C to serial adapter lets you connect your USB-C devices to your legacy serial equipment. It converts a USB-C port on your laptop or computer into a RS232 DB9 serial port, giving you a cost-saving way to connect to serial devices such as point-of-sale terminals, serial modems, industrial equipment, and a wide variety of other RS232 peripherals.