Bird lovers can enjoy the sharp views and close focus of the Celestron Nature DX Binoculars. The binoculars feature phase-coated BaK-4 prisms for great contrast and resolution and fully multicoated optics for bright images. The binoculars feature a rubber-armored polycarbonate housing and twist-up eyecups with multiple stops for proper positioning of the eyes. Nitrogen purged to prevent internal fogging and waterproof to keep out the elements.