Toner cartridge is designed for use in Lexmark C540, C540DW, C540N, C543, C543DN, C544, C544DN, C544DTN, C544DW, C544N, C5460DTN, X543DN, X544DN, X544DTN, X544DW, X544N, X546DTN, X548DE and X548DTE. Lexmark Return Program Cartridges are sold at a discount, vs. the prices of regular cartridges, in exchange for the customer's agreement to use the cartridge only once and return it only to Lexmark for remanufacturing or recycling.