4 Port USB Manual Switch - ATEN's US401 4 Port USB Manual Switch allows up to four PCs and/or Macs to share the use of a single USB peripheral device (printer, modem, etc.), on a one-at-a-time basis. The active computer is selected by means of an electronic pushbutton switch that cycles among all of the ones that are connected. Connect one of our hubs to the downstream ports to increase the number of devices to share between computers.