Lindy 51174 interface cards/adapter

USB to Serial Converter - 4 Port, Internal The convenient, space-saving way to connect your serial devices to an internal USB port!
This clever converter board can be mounted into a spare PC case back plate slot to allow you to connect up to 4 external serial RS-232 devices to an internal USB port on a motherboard or expansion card. A space-saving alternative to USB converter cables, it's supplied with all required connection cables and back plates for use in standard and low profile PC cases.