INK4WORK 2 Pack CF210A Black Remanufactured HP 131A Black Toner Cartridge for Hp Laserjet Pro M251 M276 Toner Printers Black Toner Cartridge Replacment For HP CF210A (131A) ( 2Pack) Laserjet Pro M251n, M276n ISO9001 certified. Sold by ink4work. Approximate cartridge yield: Black up to 1,600 standard pages, Color up to 1,800 Standard pages (5% coverage of lettle size paper)(average continuous black, declared yield value in accordance with ISO/IEC 19798, actual yields vary considerably based on images printed, other factors.