Celestron 71331 Nature DX 10x32 Binocular (Green) BaK-4 Prisms w/ Phase Coating: Increases contrast and resolution for sharper more detailed images Fully Multi-Coated Optics: Allows maximum light transmission through the optical path for brighter images 6.5 Close Focus: Detailed, up close observation of subjects in close proximity. Ideal for watching birds, insects, plants, etc. Compact and Lightweight: Fits in a pocket or glove box; easy to carry on long excursions Twist-up Eyecups: Twist up and down with multiple stops for correct positioning of the users eyes for comfortable viewing with or without eyeglasses Polycarbonate frame: Strong and durable polycarbonate body. Provides structural integrity while keeping the weight to a minimum.