The uPCI-400i Universal PCI 4-Port industrial serial I/O card offer four independent RS-232/422/485 serial ports. This Industrial I/O board supports both 3.3V and 5V PCI bus, and its compatible with 32-bit PCI, 64-bit PCI and PCI-X bus. All serial ports are built by 16550A-compatible UARTS with 16 byte FIFO. Each port may be used in different configurations of RS232, RS422 or RS485 For more details on product, Please refer to http://www.papyrus.co.il/4rs232422485upciserial.htm