Designed for exact compatibility with oki products only oki consumables ensure maximum performance longevity and ultimate cost effectiveness okis ribbon cassettes inkjet heads toner and ep cartridges and other consumables are an integral part of the fundamental design of its printer and fax products combining with other key elements of their design to deliver optimum durability reliability and print quality for use with oki c5600dn 5600n 5700dn 5700n printers approx 6000 pages