The Barska 7x30 WP Deep Sea Porro - Internal Rangefinder and Compass Binoculars are specially designed for nautical use, and they feature an internal range-finding reticle and compass for navigation. These heavy-duty binoculars have shockproof, non-slip ergonomic rubber armor for a secure grip in rugged conditions. They are O-ring-sealed to be 100% waterproof and dry-nitrogen-purged and sealed to prevent internal fogging, clouding, and moisture damage. 7x magnification allows for the steadiest images possible in rough sea conditions, and a compact 30mm objective lens provides great light transmission in a smaller, lightweight body. Fully coated optics, BAK-4 prisms, and porro lenses ensure crisp, clear imaging. These binoculars are perfect for the beginning or experienced mariner. * 100% waterproof and fogproof * Dry nitrogen-purged and sealed to prevent internal fogging * Fully Multi-Coated Optics * Internal range-finding reticle and compass * Limited Lifetime Warranty