This is Compatible HP CF217A Black MICR toner cartridge, where MICR is an acronym for Magnetic Ink Character Recognition. MICR Cartridges are used for printing checks. Banks read magnetic ink differently than standard ink, which allows them to reliably process checks. Magnetic Ink Recognition Toner; Regular toner mixed with IRON OXIDE particles, recognized by scanning devises. HP CF217A MICR toner mainly used for Check printing and bar coding; built with NEW drums and NEW components that match all ABA standards (American Bankers Association).