Genuine Canon drum units, like the colour C-EXV28, guarantee the smooth running of your imageRUNNER Advance laser printer for an amazing amount of prints. With an estimated 85,000 page yield, the Canon 2777B003BA is a component that does not need changing often, but is absolutely essential to your printer.Imaging drums like the colour Canon C-EXV28 handle all of the cyan, magenta and yellow powder from your installed toner cartridge/cartridges and apply it to paper efficiently. Whilst you may not think of the 2777B003BA tri-colour drum unit all that often, getting the quality of print you expect from your Canon IRC5255 (and all other compatible printers) depends upon this consumable.