This TruGlo Red Dot 1X 30mm Sight is an all round sight. Great for shotguns, rifles, crossbows and handguns. How's that for versitile? Features a wide field of view for quick accurate target acquisition. The multi coated lense produces 95% more light transmission and the anti reflective interior will eliminate any stray light that might come your way. The TruGlo Red Dot Sight is waterproof, fog proof and shock resistant. The boy allows high quality optics in all kinds of weather conditions. Features the Weaver integrated mounting system and includes one 3V CR2032 battery. Measures 3.8 inches long.