Pentax Papilio Binoculars with Case 8.5x21

Named for the Latin word for butterfly, PENTAX Papilio 8.5x21 binoculars are the perfect choice for insect observation in the field and in museums and galleries. The enhanced observation capability of the Papilio binoculars is made possible by a PENTAX Convergent Lens Optical System Engineering (CLOSE) mechanism. The CLOSE mechanism automatically slides the left and right objective lenses toward the center when the focus is fixed at a short distance. Features: - Ideally suited for viewing insects, birds, artwork or any other object at close ranges - C.L.O.S.E. (Convergent Lens Optical System Engineering) allows them to focus down to 1.6 feet - Tough rubber covered exterior provides a sure grip and protects the internal mechanisms - Sleek, contemporary ultra-compact body with unibody construction - Revolutionary dual-axis, single body housing with synchronized eye-piece adjustment to assure correct optical alignment for comfortable viewing - Fast and easy center focusing for handling ease - Helicoid eyepiece rings for extra viewing comfort - Fully multi-coated optics to eliminate harmful ultraviolet rays while improving light transmission for high contrast images with no glare or flare - High quality BaK4 prisms transmit more light at the edges to enhance illumination for easier viewing in dim light Specifications: Binocular Type: Center focusing, porro-prism Lens Construction: Objective Lens: 2 elements in 1 group Eyepiece Lens: 5 elements in 5 groups Magnification: 8.5X Objective Lens Diameter: 21mm Real Field of View: 6.0 degrees Apparent Field of View: 51 degrees Field Of View At 1000 Meters: 105m Field of View at 1000 Yards: 315 ft. Exit Pupil: 2.5mm Eye Relief: 15mm Prism: Porro Relative Brightness: 6.3 Diopter Adjustment Range: +/- 4m -1 Diopter Adjustment: Click-stop adjuster built in right eyepiece Eye Distance Adjustment Range: 56mm-74mm (2.2" - 2.9") Focusing Range: Approx. 0.5m (1.6 ft.) to infinity Eyepiece Ring: Helicoid type Body Color: Black & dark gray Height Width: 116mm x 110mm (4.6" x 4.3") Thickness: 55mm (2.2") Weight: 290g (10.2 oz.) Accessories: Eyepiece lens caps, Case, Neck strap Vergence Correction: Focus-coupled correction mechanism