Amazon.com: Lexmark C540, C543, C544, C546, X543, X544, X546 Series High Yield Magenta Return Program Toner Cartridge (2,000 Yield), Part Number C540H1MG : Office Products
Lexmark C540 HY Toner Set - LD Products
Lexmark C540H1KG C540H2KG Toner Cartridge Black C540 C540n C543 C543dn C544 C544dn C544dtn C544dw C544n C546 - Sun Data Supply