The Sig Sauer SOR21301 is a Romeo2 1x30mm 3MOA Reflex Sight with a large shroud. It is a durable, red dot optic designed for tactical and competitive use on compatible SIG Sauer pistols, featuring MOTAC (Motion Activated) and D.A.R.C. technology, a 3 MOA red dot reticle, and a 7075 aluminum housing. The optic can be configured in a closed, half-shroud, or open-emitter format to suit different needs for protection and weight. Model: Romeo2 SOR21301Reticle: 3 MOA red dotShroud: Large shroud for full protection; can be removed or replaced with a half shroud for different configurationsDurability: Constructed from 7075 aluminum with a ruggedized steel shroud to withstand impactsTechnology:MOTAC: Motion Activated Illumination System to power the optic on and offD.A.R.C.: Dark Adaptive Reticles & Coatings, which provides optimal reticle brightness and target clarity with night vision devicesLens: Molded aspheric glass lens with high-performance coatings for excellent light transmissionBrightness: 15 brightness settings, including 3 for night visionBattery: CR2032 battery with a side-release tray for easy changes without removing the opticCompatibility: Fits SIG Sauer pistols with the newer PRO-CUT slide