The Navyman binoculars deliver a great performance in every marine and boating environment thanks to their waterproof and nitrogen purged construction, coupled with ruby lenses that help cut glare over water or snow.  Specifications: Waterproof/fogproof  Nitrogen filled Bak-4 Prisms Special coated optics  Rubber covered Magnification xO objective: 7x50 Focusing: Central Field of view 1000 mt/yds: 123m, 410 ft Exit Pupil mm: 6.8 Weight: 868gr, 30.6oz