Extreme terraina |unimaginable weather conditions. Both test your spirita |and your optics. With a well-earned reputation for pushing the limits of optical performance, the Vortex Razor HD Roof Prism Binoculars are in a class of their own. Small, lightweight, strong and packed with the highest-quality, hand-selected prisms and premium HD extra-low dispersion glass, the Vortex Razor HDs are the only Binoculars you'll need for any outdoor adventure. Optical features: Premium HD (high density) extra-low dispersion glass delivers the ultimate in resolution and color fidelity Apochromatic optical system and HD glass combine to provide unmatched color sharpness Dielectric prism coatings provide bright, clear, color-accurate images Phase correction coating enhances resolution and contrast Premium lens coatings deliver the highest level of light transmission with multiple anti-reflective coatings on all air-to-glass surfaces for maximum brightnessConstruction features: Roof prism for greater durability and compact transport Open-hinge design provides superior ergonomics while decreasing weight and bulk Magnesium chassis decreases weight and increases strength O-ring seals prevent moisture, dust and debris from penetrating the binoculars Argon gas purging prevents internal fogging over a wide range of temperatures ArmorTek coating protects exterior lenses from scratches, oil and dirt Rubber armor shell provides a secure, non-slip grip and durable external protectionConvenience features: Multi-position eyecups for comfortable viewing with or without eyeglasses Center focus wheel allows you to focus both binocular barrels at the same time Locking diopter adjusts for differences in the user's eye Compatible with a tripod adapter