Brunton Echo Full-Size 10x42 Binocular High-quality full-size 10x power binocular for viewing over long distances 42mm objective lenses with BaK-4 prism glass and Emerald Fire multi-coating 315-foot field of view at 1,000 yards; 16mm long eye relief Waterproof and fog-proof polymer frame; eyeglass-compatible twist-up eye relief system Measures 5.7 x 5 x 2.2 inches (W x H x D) and weighs 23 ounces; 5-year warranty