Linkyo Replacement Brother TN-820 provides a sharp monochrome (black) text with a standard yield of 3,000 pages. For Brother Printers, The drum unit transfers toner powder from the toner cartridge to the page. This usually happens after the drum unit has been used for a couple of toner cartridges. DR-820 drum unit capacity of 30,000 pages and needs to be replaced after the use of 3 or 4 replacement toner cartridges. Buy replacement toner cartridges online from Linkyo to ensure a 100% Satisfaction Guarantee..