The Lexmark MFP Printer Base provides additional stability for your MFP or printer configuration when additional input drawers are used. Hardware is included for connecting the 250 or 500 Sheet Drawers, duplex unit and printer together as one unit. All input options must have connecting pins installed. This includes attachment to the printer base and to each other. The barbed tip must be installed on the unit that interfaces with the base of the printer. This option cannot attach to the duplex unit. It only attaches to a drawer.