Vortex Solo 10x25 Monocular S105 is a great 25mm to carry on your hiking or camping trips when packing super light. The Solo 10x25 Monocular by Vortex weighs less than six ounces, sealed with O-rings to prevent moisture and debris from getting into the monocular and the barrel is filled with Nitrogen gas to prevent fogging. Magnification: 10 x Objective Lens Diameter: 25 mm Eye Relief: 14.5 mm Exit Pupil: 2.5 mm Linear Field of View: 315 feet/1000 yards Angular Field of View: 6 degrees Close Focus: 16.4 feet Length: 4.4 inches Width: 1.8 inches Weight: 5.6 ounces Fully Multi-Coated Lenses increase light transmission with multiple anti-reflective coatings on all air-to-glass surfaces. Rubber Armor provides a secure, non-slip grip, and durable external protection. Adjustable Eyecup twists up and down for comfortable viewing with or without eyeglasses. Waterproof optics are sealed with O-rings to prevent moisture, dust, and debris from getting inside the monocular. Fogproof barrels are filled with nitrogen gas to inhibit internal fogging.