The Xerox built HP LJ 4050 (C4127X) Toner Cartridge. Each Xerox built HP LJ 4050(C4127X) cartridge is built with quality using stringent lab and environmental processes. Free shipping for each two unit order, unit yield is 10,000 pages. REDONDO TECHNOLOGY products use ISO 9001/14001 processes and we are an EPA Wastewise partner. Each unit has a one (1) year manufacturer’s warranty on both the toner and machine. Together we are partnered in keeping plastic and scrap out of landfills, we will recycle empty units at no charge for customers.