Celestron 20x80 SkyMaster Giant Binoculars 71018 Features: 20x magnification porro prism binocular Giant 80mm objective lens offers maximum image brightness in low-light and long-range conditions Four-element objective lens for ultra sharp focus across the field of view Multi-Coated optics for sharp, clear views Suitable for terrestrial or astronomical viewing Protective rubber covering for ultra-firm grip Large center Specifications: OPTICAL DESIGN: Porro DIAMETER: 80 mm (3.15 in) MAGNIFICATION: 20 x ANGULAR FIELD OF VIEW: 3.2° LINEAR FIELD OF VIEW (@1000 YDS): 167.57 ft (51.08 m) EXIT PUPIL: 4 mm (0.16 in) EYE RELIEF: 17 mm (0.67 in) NEAR FOCUS (BINOCULARS): 80 ft (24.38 m) PRISMS: BAK4 OPTICAL COATINGS: Multi-Coated