With light transmission, clarity and ruggedness as top priorities, Bushnell sets out to build the ultimate hunting binoculars. The Bushnell Trophy Binoculars boast a durable economic design that ensures reliable performance. Body is a heavy-duty, 100 percent waterproof/ fog proof construction with Fully multi-coated BaK-4 porro prism lenses for maximum light transmission and optimum brightness. There is a large center-focus knob for precise focusing, even while wearing gloves.