Ranging R/T Reticle; XD Lens Elements - Extra-low dispersion (XD) glass enhances resolution, color, and contrast Vortex XR proprietary anti-reflection lens coatings increase light transmission with multiple coatings on all air-to-glass surfaces; Fully Multi-Coated Lenses increase light transmission with multiple anti-reflective coatings on all air-to-glass surfaces; Roof Prism is valued for greater durability and a more compact size; The versatile, multi-position carrying clip allows quick attachment to pocket edges, equipment or vests; Twist Eyecup twists up and down for comfortable viewing with or without eyeglasses; Optics are sealed with O-rings to prevent moisture, dust, and debris from getting inside the spotting scope; Barrel is filled with argon gas to inhibit internal fogging; Ultra-hard, scratch-resistant ArmorTek coating repels oils and corrosive salts on outer glass surface