The ICUSB232SM3 3 feet USB to Serial Adaptor Cable lets you connect DB9 RS232 serial devices to your Mac or PC laptop or desktop computer through an available USB port, as though the computer offered an onboard DB9M connector. Unlike typical USB to serial converter cables where the conversion takes place at the DB9 end, the StarTech.com ICUSB232SM3 features a converter chip on the USB end. Converting at the USB source overcomes the 15 feet. technical limit of USB cables, allowing for a much greater serial DB-9 extension cable (50 feet.+ is possible depending on the application) if necessary. Simple to install and use, this USB to Serial Adaptor is a cost-effective solution that bridges the compatibility gap between modern computers and legacy serial peripherals. Backed by a StarTech.com lifetime warranty and free lifetime technical support.