Linkyo Replacement Brother TN-820 provides a sharp monochrome (black) text with a standard yield of 3000 pages. All the toner cartridges have to be inserted into the DR-820 drum unit in order to operate efficiently. A drum unit has a capacity of 30,000 pages and needs to be replaced after the use of 3 or 4 replacement toner cartridges. Our replacement toner cartridges are priced at a fraction of the original Brother cartridge cost and designed to maximize your experience.