This is a TruGlo Tru Brite Open Red Dot Multi-Reticle/Dual Color Sight. 24x34mm window for ultra fast target acquisition. 2 choices of reticle color for contrast against any target/background. 4 reticle choices for accurate targeting in any shooting condition. 5 brightness settings in both colors. Lightweight compact design, water and shock resistant. Click windage and elevation adjustment, wide field of view. Anti reflection coating on target side, parallax free from 30 yards. Integrated Weaver-style mounting system. Owner's manual and battery (3V-CR2032) included. Lifetime limited warranty from the manufacturer.