A great choice for factory, utility, and engineering applications, the Black Box® Industrial-Grade USB Hub, 4-Port enables more reliable USB device connectivity in harsh environments. The hub expands one USB port into four, so you can connect additional USB peripherals to your host system via its upstream port. Considerably more rugged than ordinary, office-grade USB hubs, it's designed to allow you to operate USB peripherals in areas with lots of electromagnetic interference (EMI) and prevent data errors caused by such interference. Tested to meet heavy industrial EMC standards, the hub is also designed to prevent ESD (electrostatic discharge) from damaging your connected USB devices-which makes it ideal for use near electronically noisy motor controls, variable frequency drives, and equipment with large electrical loads. Because the hub has high-retention ports for device connections, standard USB cables are a lot less likely to shake loose-even in environments with lots of equipment vibration. (Disconnecting them requires up to 3.2 pounds of force.) Cables click into the ports securely to help eliminate data loss. Also, because it can be powered via the USB bus, you don't need to locate it next to a power outlet. But, if your downstream USB devices require extra power, the hub can be used with an external power supply. Through its terminal block input or locking barrel plug, it receives power externally from a 10-30-VDC source. When the hub is using USB bus power, it provides a maximum of 100 mA to each downstream port; when powered externally, it provides 500 mA to each downstream port. The Hub Includes Hardware For Mounting, Including A Din Rail Mounting Bracket And Panel-Mount Brackets.