Our dual serial USB adaptor provides 2x 9 way RS-232 serial ports which can be used with modems digital cameras GPS devices scanners PDAs serial mice etc.System Requirements :USB Port A Computer capable of running one of the following Operating Systems: Windows 98SE / ME / 2000 / XP / Vista / MAC OS 8.6 / 9.x / 10.x Connector: Upstream Port: USB type A Plug (Male) Total Length 60 cms. Downstream Port: 2x D-Sub 9 Pin Connector. (Male) Host Interface: USB BUS I/O base address assigned by plug and play systems In