C540A1YG - Lexmark Yellow Return Program Toner Cartridge for C540, C543 & - MacConnection
Lexmark X544n Extra High Yield Toner Cartridge Set | eBay
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
Compatible Toner for Lexmark C544/X544 (C544X2KG) Extra HY Black