"The Bushnell H2O 10x 42 mm Porro Binocular (Clamshell Packaging) was 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 fogproof 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 powers 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.|Wide AAOV of 65.0deg|Ergonomically designed closed bridge|Locking diopter secures the viewers fine-tuned focus|BAK4 Porro prisms provide bright, clear, crisp viewing|Large center focus knob is fast, accurate, intuitive and easy to access|Twist-up eyecups for a comfortable fit with or without eye or sunglasses|Non-slip, blue, rubber armor absorbs shock while providing a soft textured rippled grip|Nitrogen purged and o-ring sealed for waterproof and fogproof all-climate performance|Multi-coated optics on at least one lens surface reduces light loss and glare due to reflection offering a brighter, higher-contrast image"