Lexmark 60F1000 601 Standard Yield black return program laser toner cartridge is essential to Lexmark print system performance, Unison & trade; Toner's unique formulation consistently delivers outstanding image quality, ensures long-life print system reliability and promotes superior sustainability all in an innovative shake-free print system. Lexmark Return Program Cartridges are sold at a discount, versus 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.