The Staples Toner Cartridge Replacement for HP 78A (Black) is a high-quality toner cartridge designed for use with compatible HP printers. This product, with the model number 31K, offers a sleek black color with a unit quantity of 1, making it an efficient and reliable choice for printing tasks. With an item height of 4.29 inches, length of 13.09 inches, and width of 6.39 inches, this toner cartridge is a convenient size for easy installation and use. The manufacturer warranty for this product is not applicable, but the product is designed for long-lasting performance.