Net Smelter Return (NSR) is the net revenue that the owner of a mining property receives from the sale of the mine's metal/non metal products less transportation and refining costs. As a royalty it refers to the fraction of net smelter return that a mine operator is obligated to pay the owner of the royalty agreement. The royalty is paid in variable or fixed payments based on sales revenue received by a mining operator in return for mining output. It is contingent only on the sales price and quantity of product sold.