This product is a genuine HP ink cartridge 4-pack in black and color, compatible with Epson and HP printers. It includes cartridges for cyan, yellow, magenta, and black ink, and is designed to work with inkjet and laser print technology. The cartridges are original HP products, specifically the 934XL/935 model, and come in one pack. The product is designed for use with the HP OfficeJet Pro 6815 printer, but may be compatible with other printers as well. The California Prop 65 warning applies to residents of California.