APO System Triplet Apochromatic lens combines with HD glass to provide unmatched color sharpness; HD Lens Elements - Premium HD (High Density) extra-low dispersion glass delivers the ultimate in resolution and color fidelity, resulting in High Definition images; XR Plus Fully Multi-Coated - Premium proprietary coatings deliver the highest level of light transmission with multiple anti-reflective coatings on all air-to-glass surfaces for maximum brightness; Dielectric Prism Coatings - Multi-layer prism coatings provide bright, clear, color-accurate images; Plasma Tech - Cutting edge application process provides unparalleled coating durability and performance; Porro Prism - Offers maximum image quality and performance in a traditional design; Straight Body Design Valued for speedy target acquisition and ease of use. Most compatible design for use with car window mounts; Waterproof O-ring seals prevent moisture, dust and debris from penetrating the spotting scope for reliable performance in all environments; Fogproof Argon gas purging prevents internal fogging over a wide range of temperatures; ArmorTek Ultra-hard, scratch-resistant coating protects exterior lenses from scratches, oil and dirt