Several variants are actually manufactured about the fighter’s lifespan. These have included the T-45A, which is a two-seat variant also used by the US Marines, and the T-45C, an upgraded version using a glass cockpit and other augments, which currently serves for a model for T-45s however in provider today. http://www.stes.tyc.edu.tw/xoops/modules/profile/userinfo.php?uid=2207551