2 Pack Ink4work Compatible C3500B001AA (128) Black Laser Toner Cartridge Fits Canon ImageClass D550, MF4412, MF4420n, MF4450, MF4550, MF4550d, MF4570dn, MF4580dn with Ink4work Wristband 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. Sold by ink4work Only. You will get 2 pack ink4work 128 black toner cartridge & ink4work rubber wristband.