The 300K Maintenance Kit contains the Imaging unit maintenance kit, pick rollers and separator rollers. It is recommended that the kit be installed at 300,000 pages.The Imaging unit maintenance kit contains a toner filter, ozone filter and a transfer roller.Compatible Printers: Lexmark XM 9145, Lexmark XM 9155, Lexmark XM 9165, Lexmark XM 9100 Series