According to the Defense Logistics Agency, National Stock Numbers (NSN) are used to identify and manage nearly every imaginable item, from aircraft parts to light bulbs. The use of NSNs facilitates the standardization of item names, supply language, characteristics and management data and aids in reducing duplicate items in the federal inventory. It also helps to standardize the military requirements for testing and evaluation of potential items of supply, as well as identifying potential duplicate items. Below, Petroleum Service Company breaks out our products by National Stock Number in order to easily identify the correct product that meets the United States government, the North Atlantic Treaty Organization (NATO), and many governments around the world requirements. Federal Agencies, including the Department of Defense (DOD), use the NSN to buy and manage billions of dollars worth of supplies yearly. Currently, there are over 6 million NSNs in the federal supply system.