The Viper HD - Premium optics and rugged construction in a tremendously compact, lightweight package - What more could you need? Well, perhaps a quality chest harness to comfortably and securely carry your investment in the field, but that's included, too! Hunters, shooters and outdoor enthusiasts alike are sure to benefit from the high performance of the Viper HD binoculars.Specifications and Features: Magnification 10 x Objective Lens Diameter 42 mm Eye Relief 17 mm Exit Pupil 4.2 mm Linear Field of View 341 feet/1000 yards Angular Field of View 6.5 degrees Close Focus 6.5 feet Interpupillary Distance 56-75 mm