From National Geographic, these binoculars feature:  Combination of fully multi-coated lenses and superior Bak-4 prisms creates images with excellent contrast and clarity 42mm aperture has ample light-gathering capability to produce bright images 10x magnification provides crisp details at mid to long distances Binoculars are waterproof and fog proof for all-weather performance Streamlined roof prism design with a sturdy single bridge 16.9mm eye relief allows eyeglass wearers to easily enjoy a full image Diopter adjustment lets users achieve proper focus for each eye to ensure a better observing experience Twist-up eyecups allow for comfortable viewing, especially for those who wear eyeglasses. Comes with lens covers, neck strap and storage case Imported.