The product is an authentic HP 21 Black Ink Cartridge (C9351AN) designed for HP printers, particularly compatible with the HP Officejet Pro 8600 model. The cartridge is in standard size and uses inkjet, pigment, and thermal print technologies to deliver high-quality black prints. It has an expiration date of 07/25 or later, ensuring freshness and optimal performance. Manufactured in Malaysia, this sealed cartridge is a reliable choice for users seeking genuine HP ink for their printing needs.