The Xerox 4050/4090/4450/4650 Laser Printing Systems Operator Guide provides step-by-step instructions on operating and caring for your Xerox 4050/4090/4450/4650 Laser Printing System (LPS). It is designed as a reference tool to help you with printer setup, all facets of printing, maintenance, and other general tasks that are part of an operator's job; therefore, it should be kept near the printer and readily available.