The TRUGLO Maxus XLE Scope Series is waterproof / fog-proof / nitrogen gas-filled. See-thru / flip-up lens caps, optical-quality / all-weather. Rubber-coated, speed-focus eye-piece. Durable leaf spring for windage and elevation adjustments. Multi-coated lenses provide maximum brightness, clarity and contrast even in the poorest of light conditions. One-piece tube made of aircraft quality aluminum. Durable, scratch-resistant, non-reflective matte finish. Lifetime Limited Warranty.