Return Program Developer Unit is essential to Lexmark Print System performance. It is designed to work best with Unison toner that consistently delivers outstanding image quality, ensures long-life system reliability and promotes superior sustainability - all in an innovative, shake-free print system. Standout performance and maximum yield are a true investment in efficiency. Developer unit yields approximately 300,000 pages in your Lexmark CX820dtfe, CX825dte, CX825dtfe, CX860dte, CX860dtfe, CX860de, CX825de, CX820de, CS820dte, CS820dtfe and CS820de. Genuine Lexmark supplies are engineered to work best together with your Lexmark printer, delivering excellent print quality from the first page to the last. Return Program Developer Unit is a patented device that is sold at a special price subject to the restriction that the developer unit may be used only once. Following the initial use, return the developer unit only to Lexmark for remanufacture and/or recycling.