Unit WorkCentre 6400 NEW 108R777. NEW SEALED Genuine Xerox 108R00777 Yellow Imaging. Xerox WorkCentre 6400 Copier, Xerox - All-in-One WorkCentre 6400S, 6400SFS, 6400X, 6400XF. GENUINE PART. Refer to the Manufacturer Part Number (MPN) at The Manufacturers’ Website for More Specs And Information.