BSA's 35mm Tactical Red/Green-Dot Sight is ready for a variety of targets. Instantly engage animals of any size by switching between the red and green reticles – red for big game, green for varmint and predator. With an 11-position rheostat, 5-MOA reticle and fully coated glass lens, it's perfect in all light conditions. Constructed of durable aluminum, you can rely on this sight season after season. Its 5/8” adjustable Weaver-style base easily mounts on any firearm. Powered by a 3-volt lithium battery (included). Length: 4”L x 3”W x 3.4”H. Weight: 11.1 oz.