Celestron 71215 Cavalry 8x42 Monocular (Olive Green) BaK-4 Prism: Increased contrast and resolution for sharper, more detailed images. Fully Multi-Coated Optics: Increased light transmission through the optical path for brighter images with increased resolution and detail. Integrated Compass: Integrated 6400mil compass for precise directional readings. Integrated reticle to calculate distance and size of objects. Waterproof and Fogproof: Ability to use in all weather conditions. Nitrogen purged to prevent internal fogging of the lenses.