The NCR 7731 Proof Machine will automatically microfilm, sort, and total checks in accordance to overseen bank standards. This machine can process payment information one customer at a time or in medium to large batches to maximize productivity. Combining your NCR Proof Machine 7731 with our Remanufactured and Genuine HP ink cartridges will create bold and smooth text on printouts. We carry the OEM / Genuine and Remanufactured HP 51604A Black Thermal Inkjet Cartridges, the Genuine HP 51605B Blue Inkjet Cartridges, and the Genuine HP 51605R Red Thermal Inkjet Cartridges which have been designed to easily fit into your NCR Cash-Register 7731 Proof Machine. Every Genuine and Remanufactured HP inkjet cartridge for your NCR printer has up to a 2 Year shelf-life and is backed with the Inkgrabber 90 Day Money Back Guarantee.