The Casio 3804 ER Calculator offers a dynamic ink delivery system, ideal for handling business or work on the go. Each Compatible Epson Black Ribbon Cartridge has a space saving design which easily installs, to reduce downtime normally spent on complicated replacement procedures. These Compatible Epson ERC-03B single black cash register ribbon cartridges have the power and durability to tackle the most demanding print tasks. The Casio 3804er printer calculator also contains a thermal ribbon, which minimizes smudging and blurring. We guarantee excellent print quality with our Compatible Epson Ribbon cartridges or we will refund your money within 90 days of purchase. And all of our Epson Ribbons for your Casio calculator have up to a 2 year shelf-life for definitive performance and convenience.