Large objective lens elements provide maximum light gathering capabilities and are perfect for use in low light conditions. Premium multi-layer coatings assure the maximum light transmission through the binocular. The result is bright, crisp, true-to-life images in the widest range of viewing conditions. Specialized protective coating repels dust, water and grease to keep your optics clean and your image quality at its peak. (SD Models Only) Rigid body construction makes these binoculars extremely rugged to maintain optical alignment. This ensures comfortable viewing throughout the life of the product. Waterproof and nitrogen-filled (JIS Class 6) to handle the most extreme weather conditions (submersible to 1m).