Konica Minolta Return Program cartridges (UAR) are patented print cartridges sold at a discount in exchange for the customer's agreement to the license requirements that the cartridges will be used only once and returned only to manufacturer for remanufacturing or recycling. These patented cartridges are licensed for single use only and will stop working after delivering a fixed amount of toner. Toner may remain in the cartridge when replacement is required. Standard replacement cartridges (STD) are sold without these restrictions.