"The Bushnell H2O 10x42mm Binocular is built to sail the ocean blue, row down a rolling river or accompany a raft on a languid lake. It has been O-ring sealed and nitrogen purged for waterproof and fog-proof protection. Immersed in water, they will still stay dry inside and the interior optical surfaces won't fog due to a rapid change in temperature or humidity. To make them even more aquatically acclimated, the protective rubber armoring is a blue color with a soft textured ridged grip so they won't slip too easily out of the hand and into the hydrosphere even when wet.The magnification of 10 power with the 42 mm objective provides excellent viewing for both close-up detail and scanning the field of view. The comfortable size allows the binocular to remain easy to hold, steady even on the deck of a deep-water frigate riding the ocean swells. Multi-coated lenses and premium BAK4 prism glass assure superior optics that delivers maximum light transmission and clarity. Twist-up eyecups, a dioptric ring and a large center focus knob supply comfortable, customized viewing no matter what the conditions are.|BaK-4 prisms for bright, clear, crisp viewing|Multi-coated optics for superior light transmission|100% waterproof: O-ring sealed and nitrogen purged for reliable, fog-free performance|Non-slip rubber armor absorbs shock while providing a firm grip|Twist-up eyecups|Large center-focus knob for easy adjustments|Longer eye relief"