Celestron 71361 LandScout 8X40 Porro Binocular (Black) Fully multi-coated optics and BaK-4 prisms provide improved contrast and resolution by increasing light transmission through the entire optical path. Extremely wide field of view allows you to quickly locate your subject and track it as it moves. Strong and durable aluminum housing provides structural integrity while keeping weight to a minimum. Extended eye relief allows for comfortable viewing for eyeglass and non-eyeglass wearers with a full field of view. Fully waterproof for use in all weather conditions and nitrogen purged to prevent internal fogging.