What's the difference between toner cartridge and drum unit? - YouTube
Toner Bank TN660 Toner Cartridge and DR630 Drum Unit Set Compatible for Brother TN-660 DR-630 HL-L2300D HL-L2320D MFC-L2740DW HL-L2380DW (1x TN-660 Toner + 1x DR-630 Drum Unit, Black) - Walmart.com
The Difference Between a Toner Cartridge and a Drum Unit – Printer Guides and Tips from LD Products
HP 144A Black Neverstop Laser Imaging Drum W1144A - Office Depot