This is one MTI © Q2672A Yellow Toner Cartridge for HP Color LaserJet 3500, 3500n and 3550, 3550n Printers. MTI © toner cartridges are engineered to exceed industry standards of high yield and exceptional quality, and guaranteed to perform with HP LaserJet Printers. Every cartridge is factory tested and ISO approved. We offer an exclusive 30-day customer satisfaction guarantee and 1-year warranty. Our dedicated customer care staff is available 9 a.m. to 7 p.m, Monday through Saturday, to answer any questions and provide technical support.