The AZTECH TN850 Black Toner Cartridge is a 4-pack compatible with Brother printers, specifically the Brother TN850 and DR820 models. With a laser print technology, this black toner cartridge ensures high-quality, crisp and clean prints for all your printing needs. Aztech is a trusted brand in providing reliable and efficient printing solutions, making this product a great choice for those looking to replace their existing toner cartridges. Easy to install and use, this 4-pack toner cartridge set is a convenient and cost-effective option for any printing requirements.