The LM-ERDS (LaserMax-Enclosed Red Dot Sight) is a robust fully enclosed sight for mourning on RMR or MOS optics ready pistols. the housing is constructed of aircraft grade 7071 aluminum. The LM=ERDS comes equipped with an industry first external forward-facing light sensor which automatically adjust the brightness of the red dot based on ambient lighting conditions. A RMR and Glock MOS mounting base plates are included. Features: External Forward-Facing Light Sensor for Auto Brightness Management 50,000 hour run time on mid setting Brightness settings: 8 Day / 2 Night Shake to awake Reticle: 3 MOA Red Dot Winadage/Elevation Adjustment: 1 click = 1 MOA Operation Modes: Auto brightness or manual adjust RMR and Glock MOS base plates included Power Source: CR2032, included