"The Bushnell H2O 7x 50 mm Binocular presents a large 50 mm objective to deliver lots of light transmission for low-light conditions that makes this Porro binocular a perfect choice for the twilight of dusk and dawn. It also becomes an important feature during overcast weather. O-ring sealed and nitrogen purged with a unique micro-ridged rubber armor covering that hinders slippery holds when wet. This binocular was made for H2O viewing situations.The optics is excellent, boasting BAK4 prisms and multi-coatings that pass through bright, clear, high contrasted images. Twist-up eyecups allow comfortable viewing for those with or without eye or sunglasses. The large center focusing knob makes focusing easy and quickly accessible even when wet.|Very generous eye relief of 20mm|BAK4 Porro prisms deliver bright, clear, crisp viewing|Large center-focus knob is easy to put your finger on even when wet|Twist-up eyecups and a right eye diopter customize these binoculars to personal preference|The housing is o-ring sealed and purged with bone-dry nitrogen to ensure all-weather performance|Multicoated optics reduces light loss and glare due to reflection offering a brighter, higher-contrast image|Rubber armoring with soft textured ridges ensures a secure, comfortable grip and added shock-resistance as well"