MICR toner cartridge is designed for use with HP LaserJet 4200 Series Intelligent Printers: 4200, 4200n, 4200tn, 4200dtn, 4200dtns & 4200dtnsl. Cartridge contains magnetic image character-recognition ink for security purposes in printing checks. Smart print cartridge is estimated to yield 12,000 pages at 5 percent coverage.