The toner cartridge yields up to 12,000 pages when printing at 5% coverage on A4/Letter sized paper. When you see the Toner Low error message you should order a new toner cartridge as the toner will run-out soon. Contact your Brother reseller for ordering information.Compatible Printers: Brother HL-7050 NLDT, Brother HL-7050 NLT, Brother HL-7050 N, Brother HL-7050, Brother HL-7050 Series