Compatible Brand LC-41BK Black Inkjet Cartridge fully compatible with the Brother IntelliFax 1840c, 2440c, 1940CN, 2440C, MFC-3340CN, 210C, 215C, 3240C, 420cn, 425CN, 5440CN, 5840CN, 620CN, 640CW, 820cw, DCP-110C, 115C, 120C, 315CN. The use of compatible supplies does not void your printer warranty.