Bright, multicoated lenses and BaK4 high index prisms: Deliver bright, high-resolution images.Smooth central focus knob: Fast range of focus for quick viewing. No bird goes unseen.Ergonomic body design: Comfortable for extended viewing.Waterproof/fogproof: Nitrogen filled and O-ring sealed.Long eye relief: For a clear and comfortable view, especially for people who wear eyeglasses.Unique click-stop, twist-out eyecup design: Delivers both long eye relief and variable eye relief to customize these binoculars to your eyes and accommodate glasses.Durable and protective, rubber-armored coating: Provides a sure, non-slip grip, wet or dry.Manufactured responsibly with lead and arsenic-free Eco-Glass