Add an RS232 serial port to your laptop or desktop computer through USB (Universal Serial Bus) The ICUSB232SM3 3ft USB (Universal Serial Bus) to Serial Adapter Cable lets you connect DB9 RS232 serial devices to your Mac or PC laptop or desktop computer through an available USB (Universal Serial Bus) port, as though the computer offered an onboard DB9M connector. Unlike typical USB (Universal Serial Bus) to serial converter cables where the conversion takes place at the DB9 end, the Star Tech.com ICUSB232SM3 features a converter chip on the USB (Universal Serial Bus) end. Converting at the USB (Universal Serial Bus) source overcomes the 15ft. technical limit of USB (Universal Serial Bus) cables, allowing for a much greater serial DB-9 extension cable (50ft.+ is possible depending on the application) if necessary. Simple to install & use, this USB (Universal Serial Bus) to Serial adapter is a cost-effective solution that bridges the compatibility gap between modern computers & legacy serial peripherals. Backed by a Star Tech.com lifetime warranty & free lifetime technical support. " * Drawing power from the USB (Universal Serial Bus) bus saves the hassle of carrying an external power adapter for this add-on serial port * Extensive list of compatible operating systems makes this device perfect for almost any RS232 application * The converter chip on the USB (Universal Serial Bus) end of the cable allows extension of the DB9 serial over much greater distances than USB (Universal Serial Bus) extension"