Fuser Maintenance Kit installation is recommended every 300,000 pages to maintain print quality and reliability. This kit includes fuser, transfer roll and paper feed roll kit. The LCD displays 80 scheduled maintenance at each 300K page count interval. It is necessary to replace the fuser assembly, transfer roller, and feed, pick and separation rollers at this interval to maintain the print quality and reliability. Compatible with: Lexmark X850e Lexmark X850e VE3 Lexmark X850e VE4 Lexmark X852e Lexmark X854e Lexmark X860de 3 Lexmark X860de 4 Lexmark X862de 3 Lexmark X862de 4 Lexmark X862dte 3 Lexmark X862dte 4 Lexmark X864de 3 Lexmark X864de 4 Lexmark X864dhe 3 Lexmark X864dhe 4 Lexmark XM850e Lexmark XM852e Lexmark XM854e Lexmark XS860de 4 Lexmark XS862de 4 Lexmark XS864de 4