These are the binoculars from National Geographic that provide fog-free performance that makes them perfectly suited for terrestrial or maritime observation in any weather. Designed with a sealed shell that earns an IP66 waterproof rating, these binoculars owe their superior visual acuity to a BK-4 roof prism design and fully multi-coated optics that include 42mm objective lenses and a nitrogren-filled interior that prevents fogging when used while adventuring in places where temperature variations would obscure the view provided by lesser models. With a field-of-view of 384' at 1,000 yards and a brightness of 27.56, they also provide 10x magnification. Includes travel case, buoyant neck strap, and lens cleaning cloth. (1.5 lbs.)