The Belkin Bitronics Data Switch Eliminates The Inconvenience Of Swapping Cables Each Time You Change Peripherals. Connect Both Your Printer And Scanner, Quickcam, Or Tape Backup Unit - The Switch Works With All Parallel Port Devices. The Data Switch Is Also Fully Reversible, Allowing Connection Of Two PC's To A Single Device. Normal Manual Switches Can Cause Electrical Spikes When Switched, Which Can Void The Warranty On Some Devices; However, The Belkin Bitronics Data Switch Is Completely Safe For Use With All Devices, Including HP Printers. No software Needed - Simply Use It As You Would Any Manual Switch. The Bitronics Data Switch Is The Easiest, Safest Way To Share Parallel Port Devices.