This is a remanufactured/compatible HP Q6511X - Black HY MICR Toner Cartridge (12000 Yield). 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. Mainly used for Check printing and bar coding. Built with NEW drums and NEW components that match all ABA standards (American Bankers Association). This HP Q6511X MICR Toner Cartridge is a Black toner used in MICR check printing. For use in HP LaserJet 2400 2420 2420d 2420dn 2420n 2430 2430dtn 2430n 2430tn HP Printer/Scanner/Copier 2410 Troy 2420 2430 MICR printers. Compatible with MICR Cartridges: Q6511A Q6511X THN-11A THN-11X 02-81133-001 02-81134-001.