The U1EXT4U is to extend the distance between 4 USB device and a host PC. The unit consists of a Master Unit and a Remote Unit that can drive up to 4 USB devices, there is a standard Category-5 Network cable connect these two units .The patented ASIC'S (Application Specific Integrated Circuits) and other ic's are used to process and repeat USB signals. The master and remote units can be used separately by connecting a regular Cat-5/5e/6 Cable in any length (up to 150 feet). For more details on product, Please refer to http://www.papyrus.co.il/4_ports_usb_extender.htm