The EXPS2 offers true 2-eyes-open shooting and provides an unparalleled targeting experience. The all-purpose EXPS2 features easy-to-adjust side buttons and a quick-detach lever. It has a transversely-mounted lithium 123 battery. The increased height of the EXPS provides iron sight co-witness access in the lower third of the viewing window. Night Vision-Compatibility: None; Water Resistant: Submersible to 10 ft. (3 m); Mount: Quick-detach lever fits both 1 Weaver and MIL-STD-1913 rail; Power Source: One 123 lithium battery. Battery Life: 600 continuous hours at nominal setting 12 at room temp.