The SY-HUB15053 USB 2.0 to 4 Port Serial RS232 Adapter converts a single USB port into four RS232 serial ports to be used with serial devices. This Industrial Grade device can be used on applications such as: POS Printer Terminals, Networking System, PLC Instrumentation device, and Data Acquisition I/O Control Module. Fully compatible with USB 2.0 USB1.1 and USB 1.0 Support 15KV electrostatic protection Operating temperature of -40 C to +85 C USB signals: vcc, data+, data-, GND RS-232 signals: DCD, RXD, TxD, DTR, GND, DSR, RTS, CTS, RI OS SUPPORTED: Windows OS, Linux 2.4 or later