Add an RS232 Serial Port with Circuit Isolation to your Laptop or Desktop Computer, through USB (Universal Serial Bus). The ICUSB2321FIS 1-Port FTDI USB (Universal Serial Bus) to Serial RS232 Adapter Cable with Optical Isolation converts an available USB (Universal Serial Bus) 1.1 or 2.0 port into an RS232 DB9 port that can be used to connect, monitor & control your serial devices. The USB (Universal Serial Bus) to serial adapter features integrated optical isolation circuits & surge protection to protect your critical, sensitive control equipment against electrical damage, making it a viable solution for costly industrial serial devices. The versatile FTDI chipset also supports COM retention, additional customization/features, & compatibility not offered by most other solutions. Broad operating system compatibility including Windows, Windows CE, Mac OS & Linux, makes this product easy to integrate into mixed environments.