Compatible C4127X / 4127X Toner Cartridge HP LaserJet 4000, HP LaserJet 4000n, HP LaserJet 4000se, HP LaserJet 4000t, HP LaserJet 4000tn, HP LaserJet 4050 100% guaranteed to perform in HP / HEWLETT PACKARD machines that use the C4127X cartridges. 100% quality satisfaction guarantee Yield: Up to 10,000 pages. ISO 9001 Certified.