Lexmark Part# C540A1KG. C540A1CG. C540A1MG. C540A1YG Toner Cartridge Set (OEM) Set of 4 Colors - CMYK - Save when buying a set. Includes 1 each of: C540A1KG, C540A1CG, C540A1MG, C540A1YG For use in C54X/X543/X544