Celestron SkyMaster 15-35x70 Zoom Binocular Black. Ideal for astronomical viewing or for terrestrial (land) use especially over long distances. SkyMaster models feature high quality BaK-4 prisms and multi-coated optics for enhanced contrast. Celestron has designed and engineered the larger SkyMaster models to meet the special demands of extended astronomical or terrestrial viewing sessions. Lower magnification allows the user to locate a subject more easily and then zoom in for a close-up view. Multi-coated optics enhances sharpness of detail and crispness of color. High quality BaK-4 prisms provide higher light transmission for better viewing in low light conditions. Large objective diameter provides a comfortable viewing aperture at high magnification levels. Long eye relief for more comfortable for all users; essential for those wearing eyeglasses while viewing. Diopter adjustment allows for refinement of image to correct for any differences in strength between the users own eyes. Tripod adapter included to mount the binocular on a tripod for prolonged viewing sessions or simply for increased stability while observing. Limited Lifetime Warranty. Specifications for Celestron SkyMaster 15-35x70mm Porro Prism Binocular: Manufacturer: Celestron Color: Black Magnification: 15 - 35 x Objective Lens Diameter: 70 mm Prism System: Porro Prism Material: BAK4 Eye Relief: 20.3 mm Exit Pupil: 2 - 4.7 mm Field of View Linear: 111 - 38.4 ft at 1000 yds Field of View Angle: 2.2 degrees Optical Coating: Multi-Coated Binoculars Focus System: Center Focus Twilight Factor: 37.41 Interpupillary Distance: 72 mm Close Focus: 22.5 m Diopter Adjustment Range: -4 - 10 dpt Water Resistance Level: Water Resistant Length: 9 in Weight: 53 oz Condition: New Package Type: Box Included Accessories: Tripod Adapter Magnification Type: Variable Width: 9 in Height: 5 in Tripod Adaptable: Yes Fogproof: No Case: Yes Zoom: Yes Armoring: Rubber Armored Brightness Index: 12.25 Nitrogen Filled: No Package Contents: Celestron SkyMaster 15-35x70 Zoom Binocular Celestron 71013: SkyMaster 15-35x70 Zoom Binocular Black