The HWS XPS3 is the shortest and lightest night-vision compatible HWS yet. Powered by a single transverse mounted CR123 lithium battery, the XPS provides additional rail space, leaving more room for rear iron sights, magnifiers or night-vision mount. Features : Water Resistant 20 Daylight Settings and 10 Additional Settings for Gen I through III+ Night Vision Devices 0.5 MOA Per Click Windage and Elevation Adjustment