These rugged binoculars feature a lightweight magnesium chassis and are equipped with fully multi-coated optics for outstanding light transmission. Bushnells patented water-repellent RainGuard HD lens coating keeps the lenses fog-proof to deliver clear, bright views. In addition to lenses and prisms made of lead-free glass, the binoculars also feature PC-3 Phase Coating on the prisms to enhance resolution and contrast. The anti-reflection Ultra Wide Band Coating allows the maximum amount of light from the front glass back to the eyepiece for optimum brightness and true colour. These waterproof, fog-proof binoculars feature twist-up eyecups.