This is a new compatible MICR Toner Cartridge for HP LaserJet 4250 printers. It is custom built to replace HP Q5942A and Troy 02-81135-001 toner cartridges. HP LaserJet and Troy Security Printers only accept MICR cartridges that have been modified to TROY specifications. MTI © premium toner cartridges are specially engineered to include the Troy modification. All our products are all factory-tested and ISO approved. We offer an exclusive 30-day customer satisfaction guarantee and 1-year 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. Note: Using a compatible MICR cartridge will not void the printer warranty.