The two boxes contain 4 HP Laser Printer LX36 Black XL Ink Cartridge is a compatible (not OEM) high-quality black ink cartridge designed specifically for HP printers. This cartridge is compatible with models such as the HP 364XL, HP Officejet Pro 8600, and HP 564 XL, ensuring reliable and professional-quality printing results. With a print technology of laser, this cartridge is ideal for producing crisp and sharp black documents and images on a variety of printers from HP.