Engineered to be provide quality results, KonusRex binoculars feature some of the highest standards of optical integrity resulting in prime resolution and brilliance. The internal prisms have been treated with a special silver coating. The painstaking process of applying this coating produces deposits of very thin metallic films that help to achieve a 95-98 percent light transmission. Phase coated BAK-4 prisms and fully multicoated lenses further enhance the viewing experience with crisp, clear views even in low light conditions. Specs Magnification 10X, Objective Diameter 42mm, Focus System Center wheel, Field of View at 1000 yds./m 319 ft. / 106 m, Close Focus 10.5 ft. / 3.2 m, Exit Pupil 4.2mm, Weight 17.6 oz. / 550 gr. Konus KonusRex Binocular 10x42mm