Features Lifetime Warranty with registration* ED Glass - Extra-Low Dispersion Glass Waterproof Fog-proof BK4 Optics PXA Phase Coating Magnesium Housing Fully Multi-Coated Description Birders, hikers, and other outdoor adventurers will be amazed at the intense details and true color Alpen Optics&'; new Chisos ED binoculars can capture. The superior optics in these binoculars combine extra-low dispersion optical glass, phase-coated prisms and fully broadband multi-coated lenses to produce images with astounding clarity and contrast. The brightness is enhanced by the large 42mm and 50mm apertures, which are sized to bring in lots of light to generate brilliant images. The Chisos ED binoculars also offer a close focus between 2m and 2.5 m, which is ideal for birdwatchers looking to maximize the tiny details they can observe in nearby subjects. Each model is waterproof and nitrogen-purged to create an internal environment that is impervious to fog and fine debris. For ease of use, they have a sleek roof prism design, a textured gripping surface and twist-up eyecups. Specs Item Number 917 Magnification 10x Waterproof Yes FOV @1000yds 305ft Coatings FMC Apparent FOV 7Adeg Eye Relief 16mm Exit Pupil 4.2mm Prism Roof BK4 Close Focus 6.5ft Eyecup Type Twist-Up Weight 759g Warranty *USA Limited Lifetime Warranty when product is registered within 60 days of purchase. Click Here to register. CA Residents: Prop 65 WARNING(S)