Developer unit is essential to Lexmark Print System Performance and works best with Unison Toner for consistently outstanding image quality. Genuine Lexmark supplies are engineered to work best together with your Lexmark printer, delivering excellent print quality from the first page to the last. This developer unit is designed for use in Lexmark CS820de, CS820dte, CS820dtfe, CX820de, CX820dtfe, CX825de, CX825dte, CX825dtfe, CX860dte, CX860dtfe and CX860de. Standout performance and maximum yield deliver a true investment in efficiency and your professional future. Part of a shake-free print system, the developer unit yields approximately 300,000 pages.