VersaToner - 42A Q5942A MICR Toner Cartridge for Check Printing - Compatible with LaserJet 4240, 4250, 4350 Magnetic (MICR) compliance toner gurantees that your printed checks will comply with US Federal and Canadian Bank Regulations and is superior for Checks, Documents and Barcodes. When small businesses or consumers use desktop software to make checks, they should always use special magnetic ink or toner. Compatible with LaserJet 4240N, LaserJet 4250 Series, LaserJet 4350 Series 10,000 Page Yield