Ink4work Remanufactured 44574301 Drum Unit Fits Okidata B411d/B411dn/B431d/B431dn Drum Unit Approximate cartridge yield: up to 30,000 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 only by ink4work Not made by okidata