bag KG toner powder refill for Lexmark Optra C540/C543/C544/C546/X543 /X544/X548/C540n/C544dn/C540A1CG/C540A1KG/C540A1MG/C540A1YG|Toner Powder| - AliExpress
Lexmark X543 Toner Cartridges
Lexmark C 534 DN Toner Cartridge Replacement - user guide (C5220KS/CS/MS/YS; C5240CH/KH/MH/YH) - YouTube