Lexmark C736H1KG High-Yield Black Toner Cartridge Prints sharp blacks and smooth grays. Uses toner optimally. Quick to install and simple to replace. 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.