Genuine OEM Brother Fuser Assembly Unit 110V for Color Laser Printer All-in-one DCP-9040CN, DCP-9045CDN HL-4040CDN HL-4040CN HL-4070CDW MFC-9440CN MFC-9450CDN MFC-9840CDW Fuser kits replace the heating element in Laser printers that fuses toner onto paper. These elements wear out from normal use, and many printers need a new fuser every 60,000 pages. When the fuser is worn or damaged, you will get fuser error/ fuser failure from your printer For use in DCP-9040CN, DCP-9045CDN, HL-4040CDN, HL-4040CN, HL-4070CDW, MFC-9440CN, MFC-9450CDN, MFC-9840CDW printers.