The Deep Sea Series is designed specifically for the nautical and boating enthusiast. With 7X magnification most popular size because of the steady image achievable under rough sea conditions and exceptional optics, these binoculars provide clear views of marine observation form sunrise to sundown. In addition, selected models include an internal rangefinder and directional compass for navigation. The Deep Sea series includes a wide range of seaworthy roof and porro styles and sizes to meet the needs of the experienced or beginning mariner. There's even a Deep Sea model that floats! All Deep Sea models feature a rugged rubber armor covering that provides a sure and secure grip. Backed by the manufacturer's Limited Lifetime Warranty FEATURES 7x magnification with 50mm objective lens and O ring sealed for complete waterproof protection Fully coated optics maximizes light transmission With internal Rangefinder and Directional compass Porro prism binocular with BAK 4 prism Bon