The 15x56 Conquest HD Binocular from Zeiss is designed to provide optimal performance in all light and weather conditions. Their performance comes from a combination of extra-low dispersion (ED) glass, and fully multicoated lenses and prisms. The ED glass corrects for chromatic aberration across the entire field of view, ensuring true color transmission with little to no distortion. Taking full advantage of the large 56mm objectives, the lenses have Zeiss' T* anti-reflective coatings, which minimize light loss and maximize the amount of light getting through the optics. The prisms are phase-corrected to increase contrast. These optical coatings and glass produce a binocular that performs well, especially in low-light conditions, with bright high-contrast images and true color transmission across the entire 69° wide-angle field of view. Designed for rigorous use in the field, they are nitrogen-filled and o-ring sealed for water and fogproof performance year-round in all weather conditions. The large center focus wheel is accessible with either hand and easy to use, even with gloves. Rubber armoring on the outside of the body provides a safe and secure non-slip grip in wet or cold conditions, and offers protection against drops and impacts. The click-stop twist-up eyecups let you customize your eye-relief whether you wear glasses or not. If you're going to be glassing for prolonged periods, the Conquest HD is tripod mountable with the included adapter.