MICR toner cartridge is designed for use with HP LaserJet 2400 series Intelligent Printers: 2420, 2420d, 2420n, 2420dn, 2430t, 2430tn and 2430dtn. Cartridge contains magnetic image character-recognition ink for security purposes in printing checks. Smart print cartridge is estimated to yield 6,000 pages at 5 percent coverage.