This is a new premium compatible MICR Cartridge designed for HP LaserJet 2420, 2420d, 2420dn, 2420n, 2430dtn, 2430n, 2430tn and Troy MICR 2420, 2430 printers. It is custom built to replace HP Q6511A and Troy 02-81133-001 toner cartridges. HP LaserJet Printers only accept MICR cartridges that have been modified to TROY specifications. MTI © premium toner cartridges are specially engineered to include the TROY modification. We offer an exclusive 30-day Satisfaction Guarantee and 1-year Manufacturer Warranty. Our dedicated customer care staff is available 9 a.m. to 7 p.m, Monday through Saturday, to answer any questions and provide technical support.