This sight is smaller than the former N-cell batter sight (511/551), and it is waterproof to 10 meters. It runs on a single CR123A battery, and it has a longer battery life than the N-cell style sights. With the single battery configuration, the XPS allows more rail space than ever, leaving more room for rear iron sights or NV mount. Smaller, lighter and always fast; the XPS series is a great addition. This Holographic Weapon Sight is night vision compatible with up to 10 settings for NV use.Get more real estate on your rail for more mission-ready options with our compact Model XPS3 HWS, our shortest and lightest HWS night vision compatible sight. Powered by a single CR123 battery, the water-resistant XPS leaves you plenty of room for rear iron sights, magnifiers, or night vision devices. The XPS3 is smaller and lighter than all other holographic weapon sights but just as fast. Law enforcement officers and hunters appreciate the light weight and compact size for carrying convenience on the job and in the woods. The XPS3 runs on a single 123 battery. The single-lithium-battery configuration allows more rail space, leaving more room for rear-iron sights, magnifiers, or a night vision mount. Feature: 20 daylight settings brightness 10 additional settings for Gen I through III+ night vision devices 1000 continuous hours battery life at nominal setting 12 at room temperature Water-resistant -33 feet depth