The Casio PJ 20L Calculator offers a dynamic ink delivery system, ideal for handling business or work on the go. Each Remanufactured and Genuine HP Inkjet Cartridge has a space saving design which easily installs, to reduce downtime normally spent on complicated replacement procedures. We carry the OEM / Genuine and Remanufactured HP 51604A black thermal inkjet cartridges, as well as our Genuine HP 51605B blue inkjet cartridges and HP 51605R red inkjet cartridges. The Casio pj20l printer calculator also contains a thermal ribbon, which minimizes smudging and blurring. We guarantee excellent print quality with our Genuine and Remanufactured HP Inkjet cartridges or we will refund your money within 90 days of purchase. And all of our HP Inks for your Casio calculator have up to a 2 year shelf-life for definitive performance convenience.