The Genuine HP Color LaserJet C4191A Black Toner Cartridge is specifically designed for use with the HP 4500 and 4550 Series printers. As an OEM product from HP, you can trust that this toner cartridge will provide high-quality printing results with vibrant black colors. Compatible with the 4550 model, this genuine cartridge ensures optimal performance and reliability for all your printing needs. Upgrade your printing experience with this reliable and efficient black toner cartridge from HP.