Overview Get the best results from your HP printing system. HP Smart technology and chemically-grown toner formulas in HP 645A LaserJet Toner Cartridges work with your printer to deliver accurate consistent color and reliable cost-effective performance. Ideal for producing the sharp black text and professional-quality graphics you need—page after page—at the speeds your printer was built for. Take pride in high-quality prints with Original HP Toner. Ensure that your printing is right the first time and every time. The choice you can trust to help avoid reprints and wasted supplies. Choose Original HP Supplies designed for reliability and consistency. Benefits Original HP cartridge designed for reliability and consistency Standard size when you need just one ~12 000 pages Features Outstanding color Consistently accurate color and precise images with HP chemically-grown toner Reliable cost-effective Cost-effective operation with all-in-one HP toner cartridges Easy to use Easy to use automatic alerts on-line ordering with HP Smart printing technology Disclaimers Using genuine HP supplies ensures availability of all HP printing features. Available with the HP Color laserJet 5550 Printer only. This feature enables users to print up to 500 pages in black after a color cartridge runs out. Available with the HP Color LaserJet 5550 Printers only.