INK4WORK Compatible Toner Cartridge For 2 PACK Compatible Canon 128 CRG-128 to use with ImageClass D550, MF4412 MF4420n MF4450 MF4550 MF4550d MF4570dn MF4580dn (Black, 2-Pack) Approximate cartridge yield: up to 2,100 standard pages (average continuous black, declared yield value in accordance with ISO/IEC 19798, actual yields vary considerably based on images printed, other factors. ISO9001 certified.