The StarTech 24-Inch Internal Motherboard USB Header to Serial RS232 Adapter lets you add an RS232 port to any desktop system that is equipped with an available USB motherboard header. This adapter supports a large number of operating systems and Microsoft WHQL-certified drivers. Unlike standard USB to serial cables, this motherboard USB adapter is designed for use inside the PC case, affording an entirely internal solution with no mess or extra adapters needed. The COM port retention feature of this adapter ensures that the port associated with this card is given the same COM port number through a reboot. This compact and simple USB to RS232 serial DB9 adapter offers a cost-effective solution that bridges the compatibility gap between modern computers and legacy serial peripherals.