VERSATILE, ALL-AROUND BINOCULARS: These binoculars are a great choice for birdwatching, nature observation, the trail, stadium, arena, or anywhere you want a close-up view of the action without sacrificing brightness or detail BaK-4 PRISMS FOR OPTIMAL VIEWING EXPERIENCE: The prisms inside Nature DX feature quality BaK-4 glass with phase coatings applied to maximize light transmission and enhance bright, highly detailed images. DURABLE, WEATHER-RESISTANT BODY: A rubber-armored, polycarbonate housing protects your binoculars from damage and stands up to even the toughest weather conditions. They're also fully waterproof and nitrogen purged to prevent internal fogging of the lenses.