The USB2-SERIALDUAL is a USB to Serial RS-232 Cable provides 2 RS-232 Serial (DB-9 male) connectors via one standard USB port. You can instantly enjoy connectivity with your Modem PDA POS or other serial devices on your PC or Mac without the hassle of opening your computer case. It provides a quick simple and cost-effective solution and is ideal for various communication and automation applications. Specification: Compatible with USB Specification v1.1 and v2.0 (Full-Speed). Supports 2 port Serial ports at the same time. Supports all common RS-232 Serial Port. Automatic USB Protocol handling. Supports remote wake-up and power management. USB bus powered no external power supply required. Prolific Chipset System Requirements: Available USB port Windows 2000 Windows XP Windows Vista Windows 7 Mac 10.4/5