The ColorSphere toner of the HP LaserJet 51A Black Print Cartridge produces sharp blacks and greater dynamic range when printing brilliant color. Reliable HP Color LaserJet print cartridge technology means that photo-quality business printing is fast, simple and hassle-free. Incorporating HP Smart technology the cartridge is finely tuned to the unique properties of HP's ColorSphere toner, enabling the print cartridges and the printer to trigger adjustments that optimize print quality and reliability. This cartridge will yield approximately 6,500 standard pages. It is for use with HP LaserJet P3005, M3035 & M3027 MFP series printers. Q7551A