This military-grade liquid crystal technology was created as a result of Department of Defense funding for Air Force pilots and war fighters who experience rapidly changing lighting conditions and depend on optimal lighting to perform at the highest levels. The liquid crystal (LC)-based electronic tint-on-demand or e-Tint® on flexible lenses can switch rapidly between clear and tinted states at the touch of a button or automatically. These rapid transitions occur within 1/10 of a second providing a tactical advantage for the end user. In addition, ballistic properties adhere to MIL-PRF-32432A and ANSI Z87.1 requirements. Comes with USB charging cable and storage case.