Designed for a range of SCX-series printers, this genuine Samsung Imaging Unit is designed to ensure the best possible output from your printer for up to 15,000 pages. The imaging unit in your printer uses an electrostatic charge to create the text and images that are then transferred to the page with toner. Because wear and tear and excess toner build-up will reduce the performance of the imaging unit over time, Samsung recommend you replace the unit at regular intervals.