Visit Amazon sites : http://www.amazon.com/gp/product/B00F4DRIMQ?tag=gallianostore-20
USBGear? Dual Port RS-232 USB-to-Serial Plugin Adapter
Adds two RS-232 serial ports by connecting to a USB port
High speed serial port with the baud rate up to 9216K bps
Full RS-232 modem control signals and hardwaresoftware flow control
RS-232 data signals TxD RxD RTS CTS DSR DTR DCD RI GND
OS CompatibilityWindows 98 Me XP 2000 2003 CE Vista Windows 7 and Windows 8 as well as Linux and Mac OS 10X
