The Barska Naturescape binoculars are built to perform under all conditions and feature BaK-4 prisms and fully multicoated optics that deliver crisp high definition images. Focusing is smooth and precise thanks to a large center focus knob and separate diopter adjustment. Twist up locking eyepieces provide the convenience of viewing with or without eyeglasses. The optical system and chassis are encased and protected by a rubber armor covering that keeps dust and moisture out and provides a comfortable secure grip.