Genuine OEM Brother MFC-680CN Ink and Supplies
The MFC-680CN uses Brother LC-51 ink, with black, cyan, magenta, and yellow sold separately. Its grouped formats split the choice between a cyan-magenta-yellow pack and a two-pack of black.
Toner Buzz carries genuine Brother LC-51 in single-color and multipack options. Match one cartridge to one color, use the tri-color pack for the three color inks together, or choose the black pair when two black cartridges suit the order.