Brother's laser toner inks are specially formulated to ensure quality, high resolution results. With Brother laser machines the toner and drum units work independently so when one unit runs out, you don't have to replace both, resulting in reduced waste and significant cost savings. With a high print yield of approximately 4000 pages (more than double the standard cartridge yield) at 5% coverage, Brother's TN135M toner cartridge provides excellent value for money.