The M48 Patton-series saw widespread service with the United States and NATO until it was superseded by the M60 tank as well as being widely exported. The tank's hull also developed a wide variety of prototypical, utility and support vehicles such as armored recovery vehicles and bridge layers. Some M48A5 models served into the mid-1980s with US Army National Guard units and M48A3s were used as targets for weapons and radar testing into the mid-1990s. Many M48s remain in service in other countries though most of these have been highly modified and had their firepower, mobility and protection upgraded to increase their combat effectiveness on the modern battlefield. As of 2015, Turkey is the largest operator with over 750 units in service, Taiwan is second with approximately 500 upgraded variants and Greece is third with 390 in service.