Eagle Optics Denali 8x42 Roof Prism Binoculars Fully Multi-coated Lenses: Increase light transmission with multiple anti-reflective coatings on all air-to-glass surfaces. Waterproof: Optics are sealed with O-rings to prevent moisture, dust, and debris from getting inside the binocular. Fogproof: Barrels are filled with nitrogen gas to inhibit internal fogging. Rubber Armoring: Provides a secure, non-slip grip., Adjustable Eyecups: Twist up and down for comfortable viewing with or without eyeglasses., Center Focus Wheel: Adjusts both binocular barrels at the same time. Right Eye Diopter: Adjusts for differences in a user's eyes, Located by the right eyepiece., Tripod Adaptable: Can be mounted using standard 1/4-inch threading. Adapter sold separately.