IOGEAR's USB 2.0 Automatic Printer Switch allows four PCs and / or Macs to share one printer or multi-function printer. Simply submit a print job and the printer automatically switches to the preferred computer. The switch also enables four computers to easily share one external hard drive, scanner, or any USB device. No more plugging and unplugging between computers.Automatic switch function is software based and only available with USB printer or the printer function of a multi-function printer. For connecting and using other types of USB devices, you can switch by using the push-button on the USB switch or with the included software.