The SCRS-RD-MRS & SCRS-GR-MRS (Solar Charging Rifle Sight) advances Holosun's SCS technology creating an all-new, ultra compact 20mm tube sight designed for rifle applications. SCRS features multi-directional light sensors and an advanced Auto Mode for automatic reticle intensity settings and Manual Mode for manual control of dot intensity. SCRS is made from 7075 aluminum and utilizes Holosun's 509T footprint for compatibility with third party offset RDS mounts. The SCRS-RD-MRS features their Red MRS (Multi-Reticle System) and SCRS-GR-MRS features their Green MRS. 20,000-Hour Power Reserve Multi-Sensor Auto Brightness Solar Charging Internal Battery Mfg: Holosun