BARSKA Deep Sea 7x25 Waterproof Binocular O-ring sealed for complete waterproof protection and Dry nitrogen-purged and sealed to prevent fogging and moisture damage in all weather conditions Fully coated optics for increased clarity with BAK-4 prism for crisp images Optimum long eye relief with fold-down eyecups Ergonomic rubber armor that is compact and durable Features a rugged rubber armor covering that provides a non-slip and secure grip, designed specially for nautical use