Vortex Optics Features Fully Multi-Coated Lenses: Increase light transmission with multiple anti-reflective coatings on all air-to-glass surfaces Phase Correction: Used on roof prism models only-coating enhances resolution and contrast Roof Prisms: Valued for greater durability and a more compact size Waterproof: Optics are sealed with o-rings to prevent moisture, dust and debris from getting inside the binocular Fogproof: Argon gas purging guarantees superior fogproof and waterproof performance Rubber Armor: Provides a secure, non-slip grip and durable external protection Multi-Position Eyecups: Twist up and down to precise, intermediate settings to maximize custom fit for comfortable viewing with or without eyeglasses Center Focus Wheel: Adjusts the focus of both binocular barrels at the same time Right Eye Diopter: Adjusts for differences in a user's eyes. Located on the right eyepiece Tripod Adaptable: Compatible with a tripod adapter, allowing use on a tripod or car window mount. Adapter sold separately Vortex Optics Specifications Magnification 10 x Objective Lens Diameter 32 mm / 1.25" Eye Relief 10 mm / 0.39" Exit Pupil 3.2 mm / 0.12" Linear Field of View 341 feet/1000 yards Angular Field Of View 6.5 degrees Close Focus 8 feet / 2.43 m Interpupillary Distance 59-74 mm / 2.32-2.91 inch Dimensions 4.5 x 5.3 inches / 11.43 x 13.46 cm Weight 18.8 g / 0.66 oz