With the Vortex Viper HD 10x42, you're getting binoculars with exceptional optical properties. It features ED lenses, XR coatings, and phase coatings. Together, all of these features ensure an optimal light transmission, so the world comes into clear view through the lenses. These binoculars can be considered HD binoculars, and rightly so. But the Vortex Viper HD 10x42 isn't just well-put together optically. The Armortek coating protects the lenses from dirt and water. The binoculars are also completely waterproof, thanks to the argon filling and the isolation with O rings. The elements won't stand a chance.